added config switch to disable decimal mode tests

decimal mode tests can be disabled for the ADC & SBC instructions or
also including the decimal mode bit of the processor status register.
This commit is contained in:
Klaus2m5 2015-10-21 16:51:23 +02:00
parent d0cd6d09af
commit 54768c6dc0
2 changed files with 433 additions and 7 deletions

355
6502_decimal_test.a65 Normal file
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@ -0,0 +1,355 @@
; Verify decimal mode behavior
; Written by Bruce Clark. This code is public domain.
; see http://www.6502.org/tutorials/decimal_mode.html
;
; Returns:
; ERROR = 0 if the test passed
; ERROR = 1 if the test failed
; modify the code at the DONE label for desired program end
;
; This routine requires 17 bytes of RAM -- 1 byte each for:
; AR, CF, DA, DNVZC, ERROR, HA, HNVZC, N1, N1H, N1L, N2, N2L, NF, VF, and ZF
; and 2 bytes for N2H
;
; Variables:
; N1 and N2 are the two numbers to be added or subtracted
; N1H, N1L, N2H, and N2L are the upper 4 bits and lower 4 bits of N1 and N2
; DA and DNVZC are the actual accumulator and flag results in decimal mode
; HA and HNVZC are the accumulator and flag results when N1 and N2 are
; added or subtracted using binary arithmetic
; AR, NF, VF, ZF, and CF are the predicted decimal mode accumulator and
; flag results, calculated using binary arithmetic
;
; This program takes approximately 1 minute at 1 MHz (a few seconds more on
; a 65C02 than a 6502 or 65816)
;
; Configuration:
cputype = 0 ; 0 = 6502, 1 = 65C02, 2 = 65C816
vld_bcd = 0 ; 0 = allow invalid bcd, 1 = valid bcd only
chk_a = 1 ; check accumulator
chk_n = 0 ; check sign (negative) flag
chk_v = 0 ; check overflow flag
chk_z = 0 ; check zero flag
chk_c = 1 ; check carry flag
end_of_test macro
db $db ;execute 65C02 stop instruction
endm
bss
org 0
; operands - register Y = carry in
N1 ds 1
N2 ds 1
; binary result
HA ds 1
HNVZC ds 1
;04
; decimal result
DA ds 1
DNVZC ds 1
; predicted results
AR ds 1
NF ds 1
;08
VF ds 1
ZF ds 1
CF ds 1
ERROR ds 1
;0C
; workspace
N1L ds 1
N1H ds 1
N2L ds 1
N2H ds 2
code
org $200
TEST ldy #1 ; initialize Y (used to loop through carry flag values)
sty ERROR ; store 1 in ERROR until the test passes
lda #0 ; initialize N1 and N2
sta N1
sta N2
LOOP1 lda N2 ; N2L = N2 & $0F
and #$0F ; [1] see text
if vld_bcd = 1
cmp #$0a
bcs NEXT2
endif
sta N2L
lda N2 ; N2H = N2 & $F0
and #$F0 ; [2] see text
if vld_bcd = 1
cmp #$a0
bcs NEXT2
endif
sta N2H
ora #$0F ; N2H+1 = (N2 & $F0) + $0F
sta N2H+1
LOOP2 lda N1 ; N1L = N1 & $0F
and #$0F ; [3] see text
if vld_bcd = 1
cmp #$0a
bcs NEXT1
endif
sta N1L
lda N1 ; N1H = N1 & $F0
and #$F0 ; [4] see text
if vld_bcd = 1
cmp #$a0
bcs NEXT1
endif
sta N1H
jsr ADD
jsr A6502
jsr COMPARE
bne DONE
jsr SUB
jsr S6502
jsr COMPARE
bne DONE
NEXT1 inc N1 ; [5] see text
bne LOOP2 ; loop through all 256 values of N1
NEXT2 inc N2 ; [6] see text
bne LOOP1 ; loop through all 256 values of N2
dey
bpl LOOP1 ; loop through both values of the carry flag
lda #0 ; test passed, so store 0 in ERROR
sta ERROR
DONE
end_of_test
; Calculate the actual decimal mode accumulator and flags, the accumulator
; and flag results when N1 is added to N2 using binary arithmetic, the
; predicted accumulator result, the predicted carry flag, and the predicted
; V flag
;
ADD sed ; decimal mode
cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1
adc N2
sta DA ; actual accumulator result in decimal mode
php
pla
sta DNVZC ; actual flags result in decimal mode
cld ; binary mode
cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1
adc N2
sta HA ; accumulator result of N1+N2 using binary arithmetic
php
pla
sta HNVZC ; flags result of N1+N2 using binary arithmetic
cpy #1
lda N1L
adc N2L
cmp #$0A
ldx #0
bcc A1
inx
adc #5 ; add 6 (carry is set)
and #$0F
sec
A1 ora N1H
;
; if N1L + N2L < $0A, then add N2 & $F0
; if N1L + N2L >= $0A, then add (N2 & $F0) + $0F + 1 (carry is set)
;
adc N2H,x
php
bcs A2
cmp #$A0
bcc A3
A2 adc #$5F ; add $60 (carry is set)
sec
A3 sta AR ; predicted accumulator result
php
pla
sta CF ; predicted carry result
pla
;
; note that all 8 bits of the P register are stored in VF
;
sta VF ; predicted V flags
rts
; Calculate the actual decimal mode accumulator and flags, and the
; accumulator and flag results when N2 is subtracted from N1 using binary
; arithmetic
;
SUB sed ; decimal mode
cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1
sbc N2
sta DA ; actual accumulator result in decimal mode
php
pla
sta DNVZC ; actual flags result in decimal mode
cld ; binary mode
cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1
sbc N2
sta HA ; accumulator result of N1-N2 using binary arithmetic
php
pla
sta HNVZC ; flags result of N1-N2 using binary arithmetic
rts
if cputype != 1
; Calculate the predicted SBC accumulator result for the 6502 and 65816
;
SUB1 cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1L
sbc N2L
ldx #0
bcs S11
inx
sbc #5 ; subtract 6 (carry is clear)
and #$0F
clc
S11 ora N1H
;
; if N1L - N2L >= 0, then subtract N2 & $F0
; if N1L - N2L < 0, then subtract (N2 & $F0) + $0F + 1 (carry is clear)
;
sbc N2H,x
bcs S12
sbc #$5F ; subtract $60 (carry is clear)
S12 sta AR
rts
endif
if cputype = 1
; Calculate the predicted SBC accumulator result for the 6502 and 65C02
;
SUB2 cpy #1 ; set carry if Y = 1, clear carry if Y = 0
lda N1L
sbc N2L
ldx #0
bcs S21
inx
and #$0F
clc
S21 ora N1H
;
; if N1L - N2L >= 0, then subtract N2 & $F0
; if N1L - N2L < 0, then subtract (N2 & $F0) + $0F + 1 (carry is clear)
;
sbc N2H,x
bcs S22
sbc #$5F ; subtract $60 (carry is clear)
S22 cpx #0
beq S23
sbc #6
S23 sta AR ; predicted accumulator result
rts
endif
; Compare accumulator actual results to predicted results
;
; Return:
; Z flag = 1 (BEQ branch) if same
; Z flag = 0 (BNE branch) if different
;
COMPARE
if chk_a = 1
lda DA
cmp AR
bne C1
endif
if chk_n = 1
lda DNVZC ; [7] see text
eor NF
and #$80 ; mask off N flag
bne C1
endif
if chk_v = 1
lda DNVZC ; [8] see text
eor VF
and #$40 ; mask off V flag
bne C1 ; [9] see text
endif
if chk_z = 1
lda DNVZC
eor ZF ; mask off Z flag
and #2
bne C1 ; [10] see text
endif
if chk_c = 1
lda DNVZC
eor CF
and #1 ; mask off C flag
endif
C1 rts
; These routines store the predicted values for ADC and SBC for the 6502,
; 65C02, and 65816 in AR, CF, NF, VF, and ZF
if cputype = 0
A6502 lda VF ; 6502
;
; since all 8 bits of the P register were stored in VF, bit 7 of VF contains
; the N flag for NF
;
sta NF
lda HNVZC
sta ZF
rts
S6502 jsr SUB1
lda HNVZC
sta NF
sta VF
sta ZF
sta CF
rts
endif
if cputype = 1
A6502 lda AR ; 65C02
php
pla
sta NF
sta ZF
rts
S6502 jsr SUB2
lda AR
php
pla
sta NF
sta ZF
lda HNVZC
sta VF
sta CF
rts
endif
if cputype = 2
A6502 lda AR ; 65C816
php
pla
sta NF
sta ZF
rts
S6502 jsr SUB1
lda AR
php
pla
sta NF
sta ZF
lda HNVZC
sta VF
sta CF
rts
endif
end TEST

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@ -21,7 +21,7 @@
; addressing modes with focus on propper setting of the processor status
; register bits.
;
; version 24-aug-2015
; version 21-oct-2015
; contact info at http://2m5.de or email K@2m5.de
;
; assembled with AS65 from http://www.kingswood-consulting.co.uk/assemblers/
@ -72,6 +72,7 @@
; 23-aug-2015 added option to disable self modifying tests
; 24-aug-2015 all self modifying immediate opcodes now execute in data RAM
; added small branch offset pretest
; 21-oct-2015 added option to disable decimal mode ADC & SBC tests
; C O N F I G U R A T I O N
@ -120,6 +121,10 @@ report = 0
;leave disabled if a monitor, OS or background interrupt is allowed to alter RAM
ram_top = -1
;disable test decimal mode ADC & SBC, 0=enable, 1=disable,
;2=disable including decimal flag in processor status
disable_decimal = 0
noopt ;do not take shortcuts
;macros for error & success traps to allow user modification
@ -244,12 +249,16 @@ fnv equ minus+overfl
fao equ break+reserv ;bits always on after PHP, BRK
fai equ fao+intdis ;+ forced interrupt disable
faod equ fao+decmode ;+ ignore decimal
faid equ fai+decmode ;+ ignore decimal
m8 equ $ff ;8 bit mask
m8i equ $ff&~intdis ;8 bit mask - interrupt disable
;macros to allow masking of status bits.
;masking test of decimal bit
;masking of interrupt enable/disable on load and compare
;masking of always on bits after PHP or BRK (unused & break) on compare
if disable_decimal < 2
if I_flag = 0
load_flag macro
lda #\1&m8i ;force enable interrupts (mask I)
@ -298,6 +307,64 @@ eor_flag macro
eor #\1|fao ;invert expected flags + always on bits
endm
endif
else
if I_flag = 0
load_flag macro
lda #\1&m8i ;force enable interrupts (mask I)
endm
cmp_flag macro
ora #decmode ;ignore decimal mode bit
cmp #(\1|faod)&m8i ;I_flag is always enabled + always on bits
endm
eor_flag macro
ora #decmode ;ignore decimal mode bit
eor #(\1&m8i|faod) ;mask I, invert expected flags + always on bits
endm
endif
if I_flag = 1
load_flag macro
lda #\1|intdis ;force disable interrupts
endm
cmp_flag macro
ora #decmode ;ignore decimal mode bit
cmp #(\1|faid)&m8 ;I_flag is always disabled + always on bits
endm
eor_flag macro
ora #decmode ;ignore decimal mode bit
eor #(\1|faid) ;invert expected flags + always on bits + I
endm
endif
if I_flag = 2
load_flag macro
lda #\1
ora flag_I_on ;restore I-flag
and flag_I_off
endm
cmp_flag macro
eor flag_I_on ;I_flag is never changed
ora #decmode ;ignore decimal mode bit
cmp #(\1|faod)&m8i ;expected flags + always on bits, mask I
endm
eor_flag macro
eor flag_I_on ;I_flag is never changed
ora #decmode ;ignore decimal mode bit
eor #(\1&m8i|faod) ;mask I, invert expected flags + always on bits
endm
endif
if I_flag = 3
load_flag macro
lda #\1 ;allow test to change I-flag (no mask)
endm
cmp_flag macro
ora #decmode ;ignore decimal mode bit
cmp #(\1|faod)&m8 ;expected flags + always on bits
endm
eor_flag macro
ora #decmode ;ignore decimal mode bit
eor #\1|faod ;invert expected flags + always on bits
endm
endif
endif
;macros to set (register|memory|zeropage) & status
set_stat macro ;setting flags in the processor status register
@ -501,9 +568,9 @@ ccs3\? adc zero_page,x
clc
ccs2\? inx
bne ccs3\?
ldx #hi(data_segment) ;set high byte of indirect pointer
ldx #hi(abs1) ;set high byte of indirect pointer
stx zpt+1
ldy #lo(data_bss)+15 ;data after write & execute test area
ldy #lo(abs1) ;data after write & execute test area
ccs5\? adc (zpt),y
bcc ccs4\?
inc zpt+3 ;carry to high byte
@ -764,9 +831,9 @@ gcs3 adc zero_page,x
clc
gcs2 inx
bne gcs3
ldx #hi(data_segment) ;set high byte of indirect pointer
ldx #hi(abs1) ;set high byte of indirect pointer
stx zpt+1
ldy #lo(data_bss)+15 ;data after write & execute test area
ldy #lo(abs1) ;data after write & execute test area
gcs5 adc (zpt),y
bcc gcs4
inc ram_chksm+1 ;carry to high byte
@ -4666,7 +4733,7 @@ tand1 lda zpAN,x
bpl tand1
ldx #3 ;zp
tand2 lda zpAN,x
tand2 lda zpAN,x
sta zpt
set_ax absANa,0
and zpt
@ -5101,6 +5168,7 @@ tadd1 ora adrh ;merge C to expected flags
lda ad2
sta adrl
bne tadd ;iterate op2
if disable_decimal < 1
next_test
; decimal add/subtract test
@ -5239,6 +5307,7 @@ bin_rti_ret
adc #$55
cmp #$aa
trap_ne ;expected binary result after rti D=0
endif
lda test_case
cmp #test_num
@ -5264,6 +5333,7 @@ bin_rti_ret
; S U C C E S S ************************************************
jmp start ;run again
if disable_decimal < 1
; core subroutine of the decimal add/subtract test
; *** WARNING - tests documented behavior only! ***
; only valid BCD operands are tested, N V Z flags are ignored
@ -5459,6 +5529,7 @@ chkdad
trap_ne ;bad carry
plp
rts
endif
; core subroutine of the full binary add/subtract test
; iterates through all combinations of operands and carry input