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counter_DL4YHF.asm
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counter_DL4YHF.asm
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;**************************************************************************
; FILE: counter_DL4YHF.asm *
; CONTENTS: Simple low-cost digital frequency meter using a PIC 16F628A *
; AUTHOR: Wolfgang Buescher, DL4YHF *
; (based on a work by James Hutchby, MadLab, 1996) *
; REVISIONS: (latest entry first) *
; 2020-08-25 - Ho-Ro: Modified for Linux gpsam (produces identical hex) *
; 2017-09-10 - Nigel Kendrick (nigel-dot-kendrickatgeemail.com *
; Added option to specify that you are using an external *
; crystal oscillator on OSC1, which frees OSC2/RA6/PB6 *
; as an output pin that can then be used to control display *
; digit 5 instead of the diode/transistor NAND gate. *
; 2006-05-31 - Added the 'power-save' option which temporarily puts the *
; PIC to sleep (with only the watchdog-oscillator running) *
; 2006-05-15 - New entry in the preconfigured frequency table for 4-MHz *
; IF filters (like "Miss Mosquita" [Moskita] by DK1HE) *
; 2005-08-24 - Cured a bug in the COMMON ANODE decimal point setting . *
; (the "^0xFF" for the AND-mask was missing in macro 'conv') *
; 2005-03-21 - Added a few conditionals to use the same sourcecode *
; to drive a COMMON ANODE display ( DISPLAY_VARIANT_3 ) *
; 2004-03-14 - Fixed a range-switching bug around 8 MHz . *
; - Support TWO different display variants now, *
; optimized for different board layouts, and different clock *
; frequencies (4 MHz for variant 1, 20 MHz for variant 2). *
; 2004-03-05 - Added the feature to add or subtract a frequency offset . *
; 2004-02-18 - Migration to a PIC16F628 with 4 MHz crystal (el Cheapo) *
; - Changed the LED patterns '6' and '9' because they looked *
; like 'b' and 'q' in the old counter version . *
; - Added the auto-ranging feature *
; - Stepped from 24-bit to 32-bit integer arithmetic, to be *
; able to count 50 MHz with 1-second gate time, *
; or (at least) adjust ANY result for the ANY prescaler *
; division ratio, which may give pretty large numbers . *
; - A PIC16F628 worked up to 63 MHz with this firmware . *
;**************************************************************************
list P=16F628A
#include <p16f628a.inc> ; processor specific definitions
#define DEBUG 0 ; DEBUG=1 for simulation, DEBUG=0 for real hardware
; Selection of LED display control bits... since 2005, three different variants.
; Select ONE OF THESE in MPLAB under "Project".."Build Options".."Macro Definitions"!
; DISP_VARIANT=1 : first prototype, PIC on left side of display
; DISP_VARIANT=2 : second prototype, separated PIC and display board
; DISP_VARIANT=3 : similar as (2), but for COMMON CATHODE display
; Unfortunately it seems impossible to assign a NUMERIC VALUE to a macro
; in MPLAB (not in MPASM!) ....
#ifdef DISPLAY_VARIANT_1
#define DISP_VARIANT 1 ; very first (old) prototype by DL4YHF
#define COMMON_ANODE 0
#define COMMON_CATHODE 1
#else
#ifdef DISPLAY_VARIANT_2
#define DISP_VARIANT 2 ; 5 digits, new layout, COMMON CATHODE
#define COMMON_ANODE 0
#define COMMON_CATHODE 1
#else
#ifdef DISPLAY_VARIANT_3 ; added 2005-03-21 :
#define DISP_VARIANT 3 ; similar as (2), but for COMMON ANODE display
#define COMMON_ANODE 1
#define COMMON_CATHODE 0
#else
#define DISP_VARIANT 2 ; default: 5 digits, new layout, COMMON CATHODE
#define COMMON_ANODE 0
#define COMMON_CATHODE 1
MESSG "Using default: 5 digits, new pin layout, common cathode LEDs"
#endif
#endif
#endif
;NK Define EXT_CLOCK to state that you are using an external oscillator on
;OSC1 pin (16F628 pin 16), so OSC2 pin (15) is not needed and can be used
;as RA6 to control display digit 5 instead of the transistor/diode NAND gate.
#ifdef EXT_CLOCK
#define EXTERNAL_CLOCK 1
#else
#define EXTERNAL_CLOCK 0
#endif
;**************************************************************************
; *
; Summary *
; *
;**************************************************************************
; The software functions as a frequency meter with an input signal
; range of 1 Hz to ~ 50 MHz and with an accuracy of +/- 1Hz
; if the oscillator crystal is properly trimmed .
; Signal pulses are counted over a fixed time interval of 1/4 second to
; 1 second (gate time). High frequency pulses are counted over 1/4 s
; to make the meter more responsive with no loss of displayed accuracy.
; Pulses are counted using Timer 0 of the PIC,
; which is set to increment on rising edges on the TMR0 pin. The 8-bit
; hardware register is extended by software into a 32-bit pulse counter.
; If timer 0 rolls over (msb 1 -> 0) between successive polls then the
; high two bytes of the pulse counter are incremented.
; Timer 0 is unable to count more than one pulse per instruction cycle
; (per 4 clock cycles) so the prescaler is used at frequencies above
; 1MHz (4MHz clock / 4) and also to ensure that pulses are not lost
; between polls of timer 0 (which would happen if more than 128 pulses were
; received). Fortunately the prescaler is an asynchronous counter
; which works up to a few ten MHz (sometimes as far as 60 MHz) .
; Timing is based on a software loop of known execution period . The loop
; time is 50 or 20 us which gives integer counts to time 1 s and 1/4 s .
; During this timing loop, the multiplexed LED display is updated .
; The frequency in binary is converted to decimal using a powers-of-ten
; lookup table. The binary powers of ten are repeatedly subtracted from
; the frequency to determine the individual decimal digits. The decimal
; digits are stored at the 8 bytes at 'digits'. Leading zeroes are then
; suppressed and the 4 (or 5) significant digits are converted to LED data
; for the 7-segment displays using a lookup table.
; The signal frequency is displayed on four (or five) 7-segment displays.
; The displays are multiplexed which means that only one display is enabled
; at any one time. The variable 'disp_index' contains the index of the currently
; enabled display. Each display is enabled in turn at a sufficient frequency
; that no flicker is discernable. A prescaler ('disp_timer') is used
; to set the multiplexing frequency to a few hundred Hz.
; The display shows the signal frequency in KHz or MHz, according to the
; following table:
; --------------------------
; | Frequency | Display |
; --------------------------
; | < 1Hz | 0 |
; | 1Hz | 0.001[0] | Note: kHz-dot is flashing (blinking)
; | 10Hz | 0.010[0] |
; | 100Hz | 0.100[0] |
; | 1.000KHz | 1.000[0] |
; | 10.00KHz | 10.00[0] |
; | 100.0KHz | 100.0[0] |
; | 1.000MHz | 1.000[0] | Note: MHz-dot is steady (not blinking)
; | 10.00MHz | 10.00[0] |
; --------------------------
; If there is no signal at all, a single zero is displayed in the 4th(!) digit.
; Overflows are not displayed because they cannot be detected !
;**************************************************************************
; *
; PIC config definitions *
; *
;**************************************************************************
; '__CONFIG' directive is used to embed configuration data within .asm file.
; The lables following the directive are located in the respective .inc file.
; See respective data sheet for additional information on configuration word.
; Since 2006-05-28, the watchdog must be ENABLE in the config word
; because of its wakeup-from-sleep function (see 'Sleep100ms') .
; EX(16F84:) __CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _RC_OSC
;NK If using an external clock source, use the _EXTCLK_OSC definition.
#if (EXTERNAL_CLOCK==0)
#if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz (low power, "XT" )
__CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _XT_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF
#else ; display variants 2+3 : clocked with 20 MHz (needs "HS" oscillator)
__CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _HS_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF
#endif
#else
#if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz external oscillator module
__CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _EXTCLK_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF
#else ; display variants 2+3 : clocked with 20 MHz external oscillator module
__CONFIG _CP_OFF & _WDT_ON & _PWRTE_ON & _EXTCLK_OSC & _LVP_OFF & _BODEN_OFF & _MCLRE_OFF
#endif
#endif
; '__IDLOCS' directive may be used to set the 4 * 4(?!?) ID Location Bits .
; These shall be placed in the HEX file at addresses 0x2000...0x2003 .
__IDLOCS H'1234'
; (definitions of "file" registers removed. They are defined in a header file!)
;**************************************************************************
; *
; Port assignments *
; *
;**************************************************************************
PORT_A_IO equ b'0000' ; port A I/O mode (all output)
PORT_B_IO equ b'00000000' ; port B I/O mode (all output)
LEDS_PORT equ PORTB ; 7-segment LEDs port
ENABLE_PORT equ PORTA ; display enable port
; Bitmasks to control the digit outputs have been moved to enable_table .
; YHF: Note that 'display #0' is the MOST SIGNIFICANT digit !
#define IOP_PROG_MODE PORTA,5 ; digital input signal, LOW enters programming mode
;**************************************************************************
; *
; Constants and timings *
; *
;**************************************************************************
; processor clock frequency in Hz (4MHz)
#if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz (low power consumption)
CLOCK equ .4000000
#else ; display variants 2+3 : clocked with 20 MHz (higher resolution)
CLOCK equ .20000000
#endif
; microseconds per timing loop
#if (DISP_VARIANT==1) ; display variant 1 : clocked with 4 MHz
; 20 microseconds is impossible with 4-MHz-Crystal, so use 50 us instead !
; Make sure all gate times can be divided by this interval without remainder :
; 1 second / 50 us = 20000 (ok)
; 1/4 second / 50 us = 5000 (ok)
; 1/8 second / 50 us = 2500 (ok)
TIME equ .50
#else ; display variants 2+3 : clocked with 20 MHz
; 20 microseconds is impossible with 4-MHz-Crystal, so use 50 us instead !
; Make sure all gate times can be divided by this interval without remainder :
; 1 second / 20 us = 50000 (ok)
; 1/4 second / 20 us = 12500 (ok)
; 1/8 second / 50 us = 6250 (ok)
TIME equ .20
#endif ; variant 1 or 2+3 ?
; Clock cycles per timing loop. See subroutine count_pulses .
; Usually CYCLES=200 (for 4 MHz crystal, 50 usec - loop)
; or 400 (for 20 MHz crystal, 20 usec - loop)
CYCLES equ TIME*CLOCK/.1000000
GATE_TIME_LOOPS equ CLOCK/CYCLES ; number of gate-time loops for ONE SECOND gate time
LAMPTEST_LOOPS equ CLOCK/(.2*CYCLES) ; number of loops for a 0.5 SECOND lamp test after power-on
PROGMODE_LOOPS equ CLOCK/(.10*CYCLES) ; number of delay loops for display in PROGRAMMING MODE (0.1 sec)
; Configuration of power-saving mode :
#if( DEBUG )
PSAVE_DELAY_TIME equ .10 ; number of 0.25-sec-intervals before turning off (shorter for debugging)
#else
PSAVE_DELAY_TIME equ .60 ; number of 0.25-sec-intervals before turning off (some dozen seconds)
#endif
PSAVE_FLASHUP_TIME equ .14 ; number of 0.7(!)-second-intervals between two flashes in power-saving mode
PSAVE_MAX_DIFF equ .10 ; maximum frequency difference (range-dependent, see below)
; Unit: N times "frequency-resolution", see frequency-range table .
; Example: PSAVE_MAX_DIFF=10 means 10*4Hz in Range 1 (1..3.4 MHz) .
; Menu Indices ... must match the jump table PMDisplay + PMExecute !
MI_QUIT equ 0 ; exit from menu
MI_PSAVE equ 1 ; turn "power save"-option on and off
MI_ADD equ 2 ; save frequency offset to ADD it from now on
MI_SUB equ 3 ; save frequency offset to SUBTRACT it from now on
MI_ZERO equ 4 ; set the frequency offset to ZERO and leave menu
MI_STD_IF equ 5 ; jump into the STANDARD INTERMEDIATE FREQUENCY table..
MI_INDEX_MAX equ 5 ; normal menu indices up to MI_INDEX_MAX .
MI_IF_1 equ 6 ; show the 1st standard IF
MI_IF_2 equ 7 ; show the 2nd standard IF
MI_IF_3 equ 8 ; show the 3rd standard IF
MI_IF_4 equ 9 ; show the 4th standard IF
MI_IF_5 equ 0x0A ; show the 4th standard IF
MI_IF_QT equ 0x0B ; exit standard IF menu without changing anything
MI_IF_SUBMENU_MAX equ 0x0A
;**************************************************************************
; *
; File register usage *
; *
;**************************************************************************
; RAM memory (general purpose registers, unfortunately not the same for PIC16F84 & PIC16F628)
; in PIC16F628: RAM from 0x20..0x7F (96 bytes, 0x20.. only accessable in Bank0)
; 0xA0..0xEF (another 80 bytes in Bank1)
; 0x120..0x14F (another 48 bytes in Bank2)
; 0x0F0..0x0FF, 0x170..0x17F , 0x1F0..0x1FF are mapped to 0x70..0x7F (same in all banks)
; So use 0x70..0x7F for context saving in the PIC16F628 and forget 0x0F0.. 0xNNN !
;
; Note on the 32-bit integer arithmetics as used in this code:
; - They begin with MOST SIGNIFICANT BYTE in memory, but...
; - Every byte location has its own label here, which makes debugging
; with Microchip's simulator much easier (point the mouse on the name
; of a variable to see what I mean !)
;
tens_index equ 0x27 ; index into the powers-of-ten table
divi equ 0x28 ; power of ten (32 bits)
divi_hi equ 0x28 ; same as 'divi' : HIGH byte
divi_mh equ 0x29 ; MEDIUM HIGH byte
divi_ml equ 0x2A ; MEDIUM LOW byte
divi_lo equ 0x2B ; LOW byte
timer0_old equ 0x2C ; previous reading from timer0 register
gatecnt_hi equ 0x2D ; 16-bit counter (msb first)
gatecnt_lo equ 0x2E ; 16-bit counter (lsb last)
bTemp equ 0x2F ; temporary 8-bit register,
; may be overwritten in ALL subroutines
freq equ 0x30 ; frequency in binary (32 bits)....
freq_hi equ 0x30 ; same location, begins with HIGH byte
freq_mh equ 0x31 ; ... medium high byte
freq_ml equ 0x32 ; ... medium low byte
freq_lo equ 0x33 ; ... low byte
freq2 equ 0x34 ; frequency too, copied for programming mode
freq2_hi equ 0x34 ; same location, begins with HIGH byte
freq2_mh equ 0x35 ; ... medium high byte
freq2_ml equ 0x36 ; ... medium low byte
freq2_lo equ 0x37 ; ... low byte
foffs equ 0x38 ; frequency too, copied for programming mode
foffs_hi equ 0x38 ; same location, begins with HIGH byte
foffs_mh equ 0x39 ; ... medium high byte
foffs_ml equ 0x3A ; ... medium low byte
foffs_lo equ 0x3B ; ... low byte
menu_index equ 0x3C ; menu item for programming mode
menu_timer equ 0x3D ; used to detect how long a key was pressed
digits equ 0x40 ; frequency as decimal digits (8 bytes)...
digit_0 equ 0x40 ; same location as MOST SIGNIFICANT digit, 10-MHz
digit_1 equ 0x41 ; usually the 1-MHz-digit
digit_2 equ 0x42 ; usually the 100-kHz-digit
digit_3 equ 0x43 ; usually the 10-kHz-digit
digit_4 equ 0x44 ; usually the 1-kHz-digit
digit_5 equ 0x45 ; usually the 100-Hz-digit
digit_6 equ 0x46 ; usually the 10-Hz-digit
digit_7 equ 0x47 ; usually the 1-Hz-digit
digit_8 equ 0x48 ; must contain a blank character (or trailing zero)
display0 equ 0x49 ; display #0 data
display1 equ 0x4A ; display #1 data
display2 equ 0x4B ; display #2 data
display3 equ 0x4C ; display #3 data
display4 equ 0x4D ; display #4 data
disp_index equ 0x4E ; index of the enabled display (0 to 4 for 5-digit display)
disp_timer equ 0x4F ; display multiplex timer (5 bits)
adjust_shifts equ 0x50 ; count of 'left shifts' to compensate prescaler+gate time
blinker equ 0x51 ; prescaler for the flashing 1-kHz-dot
psave_timer equ 0x52 ; timer for power-save mode (incremented every 0.25 seconds)
psave_freq_lo equ 0x53 ; low-byte of frequency to detect changes for power-save mode
psave_flags equ 0x54 ; power-saving flags with the following bits:
#define PSFLAG_ACTIVE psave_flags,0 ; clear:normal mode, set:power-saving in action (display blanked)
options equ 0x55 ; display options with the following flag-bits:
#define OPT_PWRSAVE options,0 ; clear:normal mode, set:power-saving mode enabled
;**************************************************************************
; *
; Macros (1) *
; *
;**************************************************************************
eep_dw macro value ; a DOUBLEWORD split into 4 bytes in the PIC's DATA EEPROM
de (value>>.24), (value>>.16)&0xFF, (value>>8)&0xFF, value&0xFF
endm
;**************************************************************************
; *
; EEPROM memory definitions *
; *
;**************************************************************************
; for PIC16F84: 0x00..0x3F were valid EEPROM locations (64 byte)
; for PIC16F628: 0x00..0x7F are valid EEPROM locations (128 byte)
#define EEPROM_ADR_FREQ_OFFSET 0x00 ; EEPROM location for frequency offset
#define EEPROM_ADR_STD_IF_TABLE 0x04 ; EEPROM location for standard IF table (4*4 byte)
#define EEPROM_ADR_OPTIONS 0x20 ; EEPROM location for "options" (flags)
; Initial contents of DATA EEPROM:
org (0x2100 + 2*EEPROM_ADR_FREQ_OFFSET)
eep_dw .0 ; [00..03] initial frequency offset = ZERO
org (0x2100 + 2*EEPROM_ADR_STD_IF_TABLE) ; standard IF table ...
eep_dw .455000 ; [04..07] frequently used in old AM radios
eep_dw .3999000 ; [08..0B] used in "Miss Mosquita" (DK1HE / DL QRP AG)
eep_dw .4194304 ; [0C..0F] used in other homebrew amateur radio receivers
eep_dw .4433619 ; [10..13] sometimes used in homebrew amateur radio receivers
eep_dw .10700000 ; [14..17] frequently used in old FM radios
; [18..1F] reserved for other "preprogrammed" values
org (0x2100 + 2*EEPROM_ADR_OPTIONS)
de .0 ; [20] "options" (flags), cleared by default
;**************************************************************************
; *
; More Macros *
; *
;**************************************************************************
;--------------------------------------------------------------------------
; macros to implement lookup tables - these macros hide the PIC syntax
; used and make the source code more readable
; (YHF: CAUTION - BUT THESE MACROS HIDE SOME VERY NASTY PITFALLS .
; TABLE MUST NOT CROSS PAGE BORDER DUE TO 'ADDWF PCL, f' ! )
;--------------------------------------------------------------------------
cquad macro value
retlw value>>.24 ; high byte
retlw (value>>.16)&0xFF ; middle-high byte
retlw (value>>8)&0xFF ; middle-low byte
retlw value&0xFF ; low byte
endm
table macro label ; define lookup table
label addwf PCL,f ; caution: this is 'PCL' only, cannot add to the full 'PC' in a PIC !
endm
;--------------------------------------------------------------------------
; add with carry - adds the w register and the carry flag to the file
; register reg, returns the result in <reg> with the carry flag set if overflow
;--------------------------------------------------------------------------
addcwf macro reg
local add1,add2
bnc add1 ; branch if no carry set
addwf reg , f ; add byte
incf reg , f ; add carry
skpnz
setc
goto add2
add1 addwf reg,f ; add byte
add2
endm
;--------------------------------------------------------------------------
; subtract with "no-carry" - subtracts the w register and the no-carry flag
; from the file register reg, returns the result in reg with the no carry flag
; set if underflow
;--------------------------------------------------------------------------
subncwf macro reg
local sub1,sub2
bc sub1 ; branch if carry set
subwf reg, f ; subtract byte
skpnz ; subtract no carry
clrc
decf reg , f
goto sub2
sub1 subwf reg , f ; subtract byte
sub2
endm
;--------------------------------------------------------------------------
; MACRO to perform 32-bit addition - adds the four bytes at op2 to the
; three bytes at op1 (most significant bytes first), returns the result in
; op1 with op2 unchanged and the carry flag set if overflow
;--------------------------------------------------------------------------
add32 macro op1,op2 ; op1 := op1 + op2
movfw op2+3 ; add low byte (bits 7...0)
addwf op1+3,f
movfw op2+2 ; add middle-low byte (bits 15..8)
addcwf op1+2
movfw op2+1 ; add middle-high byte (bits 23...16)
addcwf op1+1
movfw op2+0 ; add high byte (bits 31...24)
addcwf op1+0
endm
;--------------------------------------------------------------------------
; MACRO to perform 32-bit subtraction - subtracts the four bytes at op2
; from the four bytes at op1 (most significant bytes first), returns the
; result in op1 with op2 unchanged and the no carry flag set if underflow
;--------------------------------------------------------------------------
sub32 macro op1,op2 ; op1 := op1 - op2
movfw op2+3 ; subtract low byte
subwf op1+3 , f
movfw op2+2 ; subtract middle low byte
subncwf op1+2
movfw op2+1 ; subtract middle high byte
subncwf op1+1
movfw op2+0 ; subtract high byte
subncwf op1+0
endm
;--------------------------------------------------------------------------
; MACRO to negate a 32-bit value ( op := 0 - op ) .
;--------------------------------------------------------------------------
neg32 macro op ; op1 := 0 - op2
local neg_done
comf op, f ; invert all 8 bits in high byte
comf op+1, f ; invert all 8 bits in middle high byte
comf op+2, f ; invert all 8 bits in middle low byte
comf op+3, f ; invert all 8 bits in low byte
; Note at this point 0x000000 would have turned into 0xFFFFFFF .
; Must add ONE to complete the TWO's COMPLIMENT calculation ( -0 = 0 ).
; Note that "incf" affects only the Z flag but not the C flag .
incfsz op+3, f ; increment low byte (bits 7...0)
goto neg_done ; if incremented result NOT zero, we're through !
incfsz op+2, f ; increment middle low byte (bits 15...8)
goto neg_done ; if incremented result NOT zero, ...
incfsz op+1, f ; increment middle high byte (bits 23...16)
goto neg_done ; if ...
incfsz op+0, f ; increment high byte (bits 31...24)
goto neg_done ;
neg_done
endm
;**********************************************************************
ORG 0x000 ; processor reset vector
goto MainInit ; go to beginning of program
; (begin of ROM is too precious to waste for ordinary code, see below...)
;**************************************************************************
; *
; Lookup tables *
; Must be at the start of the code memory to avoid crossing pages !! *
; *
;**************************************************************************
;--------------------------------------------------------------------------
; 7-segment LED data table
;--------------------------------------------------------------------------
; Index 0..9 used for decimal numbers, all other indices defined below :
CHAR_A equ .10 ; Letters A..F = HEX digits, index 10..15
CHAR_b equ .11 ;
CHAR_c equ .12 ;
CHAR_d equ .13 ;
CHAR_E equ .14 ;
CHAR_F equ .15 ;
CHAR_G equ .16 ; Other letters used in "programming" mode
CHAR_H equ .17 ;
CHAR_i equ .18 ;
BLANK equ .19 ; blank display
TEST equ .20 ; power-on display test
CHAR_P equ .21 ; A few other letters for programming mode...
CHAR_r equ .22 ;
CHAR_o equ .23 ; "Prog"
CHAR_Q equ .24 ; "Quit"
CHAR_u equ .25 ;
CHAR_t equ .26 ;
CHAR_S equ .27 ; "Sub"
CHAR_Z equ .28 ; "ZEro"
CHAR_I equ .29 ; large "I" (left aligned!) for "IF"
CHAR_J equ .30 ;
CHAR_k equ .31 ;
CHAR_L equ .32 ;
CHAR_N equ .33 ;
CHAR_V equ .34 ;
CHAR_EQ equ .35 ; "="
#if (DISP_VARIANT==1)
DPPOINT_BIT equ 4 ; decimal point bit (same for all digits)
#define _A 0x01 ; bitmask for segment A , etc ..
#define _B 0x02
#define _C 0x20
#define _D 0x08
#define _E 0x04
#define _F 0x40
#define _G 0x80
#define _DP 0x10
#endif ; DISPLAY VARIANT #1
#if (DISP_VARIANT==2) || (DISP_VARIANT==3)
DPPOINT_BIT equ 1 ; decimal point bit (same for all digits)
#define _A 0x40 ; bitmask for segment A , etc ..
#define _B 0x80
#define _C 0x04
#define _D 0x01
#define _E 0x08
#define _F 0x10
#define _G 0x20
#define _DP 0x02
#endif ; DISPLAY VARIANT #2 + #3
BLANK_PATTERN equ b'00000000' ; blank display pattern (7-segment code)
;-----------------------------------------------------------------------------
; Table to convert a decimal digit or a special character into 7-segment-code
; Note: In DL4YHF's PIC counter, all digits have the same segment connections,
; so we do not need individual conversion tables for all segments.
;
; AAAA
; F B
; F B
; GGGG
; E C
; E C
; DDDD DP
;
;-----------------------------------------------------------------------------
Digit2SevenSeg:
addwf PCL,f ; caution: this is 'PCL' only, not 'PC'. Beware of page borders.
; A = 0, B = 1, C = 5, D = 3, E = 2, F = 6, G = 7, DP = 4
#if (COMMON_ANODE)
#define SSEG_XORMASK 0xFF ; since 2005-03-21 ... never tested by the author !
#else
#define SSEG_XORMASK 0x00 ; for COMMON CATHODE: No bitwise EXOR to the pattern
#endif
retlw (_A+_B+_C+_D+_E+_F )^SSEG_XORMASK ; ABCDEF. = '0' ( # 0 )
retlw ( _B+_C )^SSEG_XORMASK ; .BC.... = '1' ( # 1 )
retlw (_A+_B +_D+_E +_G)^SSEG_XORMASK ; AB.DE.G = '2' ( # 2 )
retlw (_A+_B+_C+_D +_G)^SSEG_XORMASK ; ABCD..G = '3' ( # 3 )
retlw ( _B+_C +_F+_G)^SSEG_XORMASK ; .BC..FG = '4' ( # 4 )
retlw (_A +_C+_D +_F+_G)^SSEG_XORMASK ; A.CD.FG = '5' ( # 5 )
retlw (_A +_C+_D+_E+_F+_G)^SSEG_XORMASK ; A.CDEFG = '6' ( # 6 )
retlw (_A+_B+_C )^SSEG_XORMASK ; ABC.... = '7' ( # 7 )
retlw (_A+_B+_C+_D+_E+_F+_G)^SSEG_XORMASK ; ABCDEFG = '8' ( # 8 )
retlw (_A+_B+_C+_D +_F+_G)^SSEG_XORMASK ; ABCD.FG = '9' ( # 9 )
retlw (_A+_B+_C +_E+_F+_G)^SSEG_XORMASK ; ABC.EFG = 'A' ( # 10 )
retlw ( _C+_D+_E+_F+_G)^SSEG_XORMASK ; ..CDEFG = 'b' ( # 11 )
retlw ( _D+_E +_G)^SSEG_XORMASK ; ...DE.G = 'c' ( # 12 )
retlw ( _B+_C+_D+_E +_G)^SSEG_XORMASK ; .BCDE.G = 'd' ( # 13 )
retlw (_A +_D+_E+_F+_G)^SSEG_XORMASK ; A..DEFG = 'E' ( # 14 )
retlw (_A +_E+_F+_G)^SSEG_XORMASK ; A...EFG = 'F' ( # 15 )
retlw (_A +_C+_D+_E+_F )^SSEG_XORMASK ; A.CDEF. = 'G' ( # 16 )
retlw ( _B+_C +_E+_F+_G)^SSEG_XORMASK ; .BC.EFG = 'H' ( # 17 )
retlw ( _E )^SSEG_XORMASK ; ....E.. = 'i' ( # 18 )
retlw (BLANK_PATTERN )^SSEG_XORMASK ; ....... = ' ' ( # 19 )
retlw (b'11111111' )^SSEG_XORMASK ; all segments on ( # 20 )
; A few more letters for programming mode :
retlw (_A+_B +_E+_F+_G)^SSEG_XORMASK ; AB..EFG = 'P' ( # 21 )
retlw ( _E +_G)^SSEG_XORMASK ; ....E.G = 'r' ( # 22 )
retlw ( _C+_D+_E +_G)^SSEG_XORMASK ; ..CDE.G = 'o' ( # 23 )
retlw (_A+_B+_C +_F+_G)^SSEG_XORMASK ; ABC..FG = 'Q' ( # 24 )
retlw ( _C+_D+_E )^SSEG_XORMASK ; ..CDE.. = 'u' ( # 25 )
retlw ( _D+_E+_F+_G)^SSEG_XORMASK ; ...DEFG = 't' ( # 26 )
retlw (_A +_C+_D +_F+_G)^SSEG_XORMASK ; A.CD.FG = 'S' ( # 27 )
retlw (_A+_B +_D+_E +_G)^SSEG_XORMASK ; AB.DE.G = 'Z' ( # 28 )
retlw ( _E+_F )^SSEG_XORMASK ; ....EF. = 'I' ( # 29 )
retlw ( _B+_C+_D )^SSEG_XORMASK ; .BCD.. = 'J' ( # 30 )
retlw ( _D+_E+_F+_G)^SSEG_XORMASK ; ...DEFG = 'k' ( # 31 )
retlw ( _D+_E+_F )^SSEG_XORMASK ; ...DEF. = 'L' ( # 32 )
retlw (_A+_B+_C +_E+_F )^SSEG_XORMASK ; ABC.EF. = 'N' ( # 33 )
retlw ( _C+_D+_E+_F )^SSEG_XORMASK ; ..CDEF. = 'V' ( # 34 )
retlw ( _D +_G)^SSEG_XORMASK ; ...D..G = '=' ( # 35 )
;--------------------------------------------------------------------------
; Table to control which 7-segment display is enabled. Displays are usually
; COMMON CATHODE (variants 1+2) so pulled low to enable.
; For DISP_VARIANT=3 (COMMON ANODE), the digit-driving pattern is inverted.
; Input: W = 0 means the MOST SIGNIFICANT DIGIT (the leftmost one), etc.
; Result: VALUE to be written to ENABLE_PORT to activate the digit
;
; NK Modified to use PA6 (RA6) if an external clock module is being used.
;--------------------------------------------------------------------------
Digit2MuxValue: ;
addwf PCL,f ; caution: this is 'PCL' only, not 'PC'
; Note: If the program counter is affected, a command requires to instruction cycles (=8 osc cycles)
#if (DISP_VARIANT==1) ; muliplexer values for DISPLAY VARIANT #1 :
retlw b'11110111' ; most significant digit is on PA3 (!)
retlw b'11111110' ; next less significant dig. on PA0 (!)
retlw b'11111011' ; next less significant dig. on PA2 (!)
retlw b'11111101' ; 4th (sometimes the last) digit PA1 (!)
#if (EXTERNAL_CLOCK==0)
retlw b'11111111' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0)
#else ; We're using an external oscillator so PA6 is used to drive 5th digit
retlw b'10111111' ; 5th (OPTIONAL) least significant digit PA6
#endif
#endif ; DISPLAY VARIANT #1
#if (DISP_VARIANT==2) ; muliplexer values for DISPLAY VARIANT #2 (5 digits, COMMON CATHODE) :
retlw b'11110111' ; most significant digit is on PA3 (!)
retlw b'11111011' ; next less significant dig. on PA2 (!!)
retlw b'11111110' ; next less significant dig. on PA0 (!!)
retlw b'11111101' ; 4th (sometimes the last) digit PA1 (!)
#if (EXTERNAL_CLOCK==0)
retlw b'11111111' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0)
#else ; We're using an external oscillator so PA6 is used to drive 5th digit
retlw b'10111111' ; 5th (OPTIONAL) least significant digit PA6
#endif
#endif ; DISPLAY VARIANT #2
#if (DISP_VARIANT==3) ; muliplexer values for DISPLAY VARIANT #3 (5 digits, COMMON ANODE) :
; Modified to cater for when PA6 is driving display digit 5.
#if (EXTERNAL_CLOCK==0)
retlw b'11111000' ; most significant digit is on PA3 (!)
retlw b'11110100' ; next less significant dig. on PA2 (!!)
retlw b'11110001' ; next less significant dig. on PA0 (!!)
retlw b'11110010' ; 4th (sometimes the last) digit PA1 (!)
retlw b'11110000' ; 5th (OPTIONAL) least significant digit = NOT (PA3+PA2+PA1+PA0)
#else ; We're using an external oscillator so PA6 is used to drive 5th digit
retlw b'10111000' ; most significant digit is on PA3 (!)
retlw b'10110100' ; next less significant dig. on PA2 (!!)
retlw b'10110001' ; next less significant dig. on PA0 (!!)
retlw b'10110010' ; 4th (sometimes the last) digit PA1 (!)
retlw b'11110000' ; 5th (OPTIONAL) least significant digit PA6
#endif
#endif ; DISPLAY VARIANT #3
;--------------------------------------------------------------------------
; Powers-of-ten table (32 bits, most significant byte first)
; Based on an idea by James Hutchby (MadLab, 1996) .
; Modified for 32-bit arithmetic by Wolfgang Buescher (2004).
;--------------------------------------------------------------------------
TensTable addwf PCL,f
cquad .10000000 ; 10 million is sufficient for the counter itself
cquad .1000000
cquad .100000
cquad .10000
cquad .1000
cquad .100
cquad .10
cquad .1
;--------------------------------------------------------------------------
; DISPLAY jump table for programming mode .
; Loads the display-strings like "quit" etc into the display latches.
; Input parameter: menu_index (0 .. MI_INDEX_MAX)
; Output placed in display0..display3
;
;--------------------------------------------------------------------------
PMDisplay:
movfw menu_index ; load menu index into W register
addwf PCL, f ; add W to lower part of program counter (computed jump)
goto PmDisp_Quit ; show "quit" (quit programming mode)
goto PmDisp_PSave; show "PSave"(power-saving mode on/off)
goto PmDisp_Add ; show "add " (add frequency offset)
goto PmDisp_Sub ; show "sub " (subtract frequency offset)
goto PmDisp_Zero ; show "Zero" (set frequency offset to zero)
goto PmDisp_StIF ; show "StdIF" (select standard IF from table)
goto PmDisp_IF_1 ; show 1st standard IF from table
goto PmDisp_IF_2 ; show 2nd standard IF from table
goto PmDisp_IF_3 ; show 3rd standard IF from table
goto PmDisp_IF_4 ; show 4th standard IF from table
goto PmDisp_IF_5 ; show 5th standard IF from table
goto PmDisp_Quit ; show "quit" (quit STANDARD IF menu)
; Add more display strings here if needed !
;--------------------------------------------------------------------------
; EXECUTION jump table for programming mode .
; Executes the commands "quit", "psave", "add", "sub", "zero", etc.
; Input parameter: menu_index (0 .. MI_INDEX_MAX)
;--------------------------------------------------------------------------
PMExecute: ; Execute the function belonging to menu_index
movfw menu_index ; load menu index into W register
addwf PCL, f ; add W to lower part of program counter (computed jump)
goto PmExec_Quit ; quit programming mode
goto PmExec_PSave; turn power-saving mode on/off
goto PmExec_Add ; add frequency offset from now on
goto PmExec_Sub ; subtract frequency offset from now on
goto PmExec_Zero ; set frequency offset to zero
goto PmExec_StIF ; switch to "Standard IF selection mode"
goto PmExec_SelIF ; select 1st standard IF from table
goto PmExec_SelIF ; select 2nd standard IF from table
goto PmExec_SelIF ; select 3rd standard IF from table
goto PmExec_SelIF ; select 4th standard IF from table
goto PmExec_Quit ; quit STANDARD IF menu
; Add more jumps here if needed !
;**************************************************************************
; *
; Procedures *
; *
;**************************************************************************
;--------------------------------------------------------------------------
; Configure the prescaler for TIMER 0 in the PIC's OPTION register .
;--------------------------------------------------------------------------
; Description of the OPTION register, from the PIC16F628 data sheet:
; bit 7: RBPU: PORTB Pull-up Enable bit
; 1 = PORTB pull-ups are disabled
; 0 = PORTB pull-ups are enabled by individual port latch values
; bit 6: INTEDG: Interrupt Edge Select bit
; 1 = Interrupt on rising edge of RB0/INT pin
; 0 = Interrupt on falling edge of RB0/INT pin
; bit 5: T0CS: TMR0 Clock Source Select bit
; 1 = Transition on RA4/T0CKI pin
; 0 = Internal instruction cycle clock (CLKOUT)
; bit 4: T0SE: TMR0 Source Edge Select bit
; 1 = Increment on high-to-low transition on RA4/T0CKI pin
; 0 = Increment on low-to-high transition on RA4/T0CKI pin
; bit 3: PSA: Prescaler Assignment bit
; 1 = Prescaler is assigned to the WDT
; 0 = Prescaler is assigned to the Timer0 module
; bit 2-0: PS2:PS0: Prescaler Rate Select bits, here shown for TMR0 :
; 000 = 1 : 2
; ... 111 = 1 : 256
; Note: to count EVERY pulse (1 : 1) with TMR0, the prescaler
; must be assigned to the WATCHDOG TIMER (WDT) !
; Some examples (for the OPTION register, parameter in W for SetPrescaler):
PSC_DIV_BY_2 equ b'00100000' ; let prescaler divide TMR0 by two
PSC_DIV_BY_4 equ b'00100001' ; let prescaler divide TMR0 by 4
PSC_DIV_BY_8 equ b'00100010' ; let prescaler divide TMR0 by 8
PSC_DIV_BY_16 equ b'00100011' ; let prescaler divide TMR0 by 16
PSC_DIV_BY_32 equ b'00100100' ; let prescaler divide TMR0 by 32
PSC_DIV_BY_64 equ b'00100101' ; let prescaler divide TMR0 by 64
PSC_DIV_BY_128 equ b'00100110' ; let prescaler divide TMR0 by 128
PSC_DIV_BY_256 equ b'00100111' ; let prescaler divide TMR0 by 256
SetPrescaler: ; copy W into OPTION register, avoid watchdog trouble
clrwdt ; recommended by Microchip ("switching prescaler assignment")
errorlevel -302 ; Turn off banking message for the next few instructions..
bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg
; option register is in bank1. i know. thanks for the warning.
movwf OPTION_REG ;! ex: "option" command (yucc)
bcf STATUS, RP0 ;! clearing RP0 for normal register access
errorlevel +302 ; Enable banking message again
retlw 0
PrescalerOff: ; turn the prescaler for TMR0 "off"
; (actually done by assigning the prescaler to the watchdog timer)
clrwdt ; clear watchdog timer
clrf TMR0 ; clear timer 0 AND PRESCALER(!)
errorlevel -302 ; Turn off banking message for the next few instructions..
bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg
; option register is in bank1. i know. thanks for the warning.
movlw b'00100111' ;! recommended by Microchip when
;! changing prescaler assignment from TMR0 to WDT
movwf OPTION_REG ;! ex: "option" command (yucc)
clrwdt ;! clear watchdog again
movlw b'00101111' ;! bit 3 set means PS assigned to WDT now
movwf OPTION_REG ;! ex: "option" command (yucc)
bcf STATUS, RP0 ;! clearing RP0 for normal register access
errorlevel +302 ; Enable banking message again
retlw 0
;--------------------------------------------------------------------------
; Power-saving subroutine: Puts the PIC to sleep for ROUGHLY 100 milliseconds .
; - crystal oscillator turned OFF during this phase
; - only the internal RC-oscillator for the watchdog keeps running
; - expiration of watchdog during sleep does NOT reset the PIC,
; only wakes it up again so normal operation may resume
; - LED display will be off during this time
;--------------------------------------------------------------------------
Sleep150ms: ; go to sleep for approx. 150 milliseconds, and then RETURN (no reset)
; Details on the PIC's watchdog timer (from PIC16F628 datasheet) :
; > The WDT has a nominal timeout period of 18 ms (with
; > no prescaler). The timeout periods vary with temperature,
; > VDD and process variations from part to part (see
; > DC specs).
; > The Watchdog Timer is a free running on-chip RC oscillator which does
; > not require any external components. This RC oscillator is separate
; > from the ER oscillator of the CLKIN pin. That means that the WDT will run,
; > even if the clock on the OSC1 and OSC2 pins of the device has been stopped,
; > for example, by execution of a SLEEP instruction.
; > During normal operation, a WDT timeout generates a device RESET.
; > If the device is in SLEEP mode, a WDT timeout causes the device to wake-up
; > and continue with normal operation.
; > The WDT can be permanently disabled by programming the configuration bit
; > WDTE as clear .
; In other words, to use the watchdog-timer for "temporary sleep" here ,
; it must be ENABLED in the configuration word when programming the PIC.
; (because its not possible to turn it on via software if it's not on).
; But once the watchdog timer is ON, it must be FED periodically otherwise
; it will reset the PIC during normal operation !
; Here (in the frequency counter), the prescaler remains assigned to timer0
; so the watchdog interval is ~ 18 milliseconds (+/-, RC-oscillator) .
; > The CLRWDT and SLEEP instructions clear the WDT and the postscaler,
; > if assigned to the WDT, and prevent it from timing out and generating
; > a device RESET. The TO bit in the STATUS register will be cleared upon
; > a Watchdog Timer timeout.
#if(COMMON_CATHODE) ; display with COMMON CATHODE :
movlw 0x00 ; segment drivers LOW to turn off
#else ; not COMMON CATHODE but COMMON ANODE:
movlw 0xFF ; segment drivers HIGH to turn off
#endif
movwf LEDS_PORT ; turn LED segments off
; Note: The global interrupt-enable flag (GIE) is off in this application !
; To avoid unintended wake-up on 'interrupt' (port level change),
; disable all interrupt-SOURCES: Clear T0IE,INTE,RBIE,PEIE too :
clrf INTCON ; disable all interrupts during SLEEP mode
clrwdt ; clear watchdog timer
clrf TMR0 ; clear timer 0 AND PRESCALER(!)
errorlevel -302 ; Turn off banking message for the next few instructions..
bsf STATUS, RP0 ;! setting RP0 enables access to OPTION reg
; option register is in bank1. i know. thanks for the warning.
movlw b'00101011' ;! assign PS to WDT; divide by 8 FOR WDT(!)
movwf OPTION_REG ;! ex: "option" command (yucc)
bcf STATUS, RP0 ;! clearing RP0 for normal register access
errorlevel +302 ; Enable banking message again
sleep ; sleep for approx 18 ms (one watchdog interval)
; The SLEEP command clears the Watchdog Timer and stops the main oscillator.
; Only the internal watchdog timer keeps running.
; The WDT is is also cleared when the device wakes-up from SLEEP,
; regardless of the source of wake-up, so no need for 'clrwdt' here !
nop ; arrived here, slept for ~ 8 times 18 milliseconds
return ; end Sleep150ms
;--------------------------------------------------------------------------
; Convert a character into LEDs data for the 7-segment displays, fed with
; the character in w. Bit 7 set means 'decimal point AFTER this digit' .
;--------------------------------------------------------------------------
conv macro display ; macro for duplicate code
movwf display ; save decimal point bit (msb)
andlw 7fh ; mask bit
call Digit2SevenSeg ; convert digit into 7-segment-code via table
btfsc display,7 ; check bit 7 = decimal point ?
#if(COMMON_CATHODE)
iorlw 1<<DPPOINT_BIT ; include decimal point if bit 7 set (bitwise OR)
#else ; not COMMON CATHODE but COMMON ANODE: decimal point must be 'AND'ed to pattern:
andlw (1<<DPPOINT_BIT)^0xFF ; include decimal point if bit 7 set (bitwise AND)
#endif
movwf display ; set display data register
endm
conv_char0: ; display digit #0 (leftmost, or MOST SIGNIFICANT digit)
conv display0
retlw 0
conv_char1: ; display #1
conv display1
retlw 0
conv_char2: ; display #2
conv display2
retlw 0
conv_char3: ; display #3
conv display3
retlw 0
conv_char4: ; display #4 (rightmost, or LEAST SIGNIFICANT digit, "ones")
conv display4
retlw 0
;--------------------------------------------------------------------------
; Fill the 5-digit display latch with blank characters
;--------------------------------------------------------------------------
ClearDisplay:
movlw BLANK_PATTERN
movwf display0
movwf display1
movwf display2
movwf display3
movwf display4
retlw 0
;--------------------------------------------------------------------------
; Save a single Byte in the PIC's Data-EEPROM.
; Input parameters:
; INDF = *FSR contains byte to be written (was once EEDATA)
; w contains EEPROM address offset (i.e. "destination index")
;
;--------------------------------------------------------------------------
; write to EEPROM data memory as explained in the 16F628 data sheet.
; EEDATA and EEADR must have been set before calling this subroutine
; (optimized for the keyer-state-machine).
; CAUTION : What the lousy datasheet DS40300B wont tell you:
; The example given there for the 16F628 is WRONG !
; All EEPROM regs are in BANK1 for the 16F628.