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Neon816: I2C2 access words

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mgcaret 2019-12-14 14:19:16 -08:00
parent f4fe6fd9e5
commit bdcbfb2766
2 changed files with 70 additions and 1 deletions
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2
platforms/Neon816/Neon816-hw.inc
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@ -75,7 +75,7 @@ RTCday = $100108 ; 2 bytes
; *****************
I2C2io = $100014
I2C2ctrl = $100015 ; read: b3 = busy; write: $01 = start, $02 = stop, $04 = receive, $08 = send, $44 = receive/ack
I2C2ctrl = $100015 ; read: b7 = busy; write: $01 = start, $02 = stop, $04 = receive, $08 = send, $44 = receive/ack
; *****************
; SPI

69
platforms/Neon816/platform-lib.s
View File

@ -141,6 +141,75 @@ dword GETRTC,"GETRTC"
EXIT
eword
; NOTE: sets short accumulator and leaves it that way on exit!
.proc I2C2_busy_wait
sep #SHORT_A
nosep:
.a8
: lda f:I2C2ctrl
rol
bcs :-
rts
.a16
.endproc
dword I2C2START,"I2C2START"
jsr I2C2_busy_wait
.a8
lda #$01
sta f:I2C2ctrl
rep #SHORT_A
.a16
NEXT
eword
dword I2C2STOP,"I2C2STOP"
jsr I2C2_busy_wait
.a8
lda #$02
sta f:I2C2ctrl
rep #SHORT_A
.a16
NEXT
eword
dword I2C2_STORE,"I2C2!"
jsr _popay
jsr I2C2_busy_wait
.a8
tya
sta f:I2C2io
lda #$08
sta f:I2C2ctrl
rep #SHORT_A
.a16
NEXT
eword
dword I2C2_FETCH_ACK,"I2C2@+"
jsr I2C2_busy_wait
.a8
lda #$44
dofetch: sta f:I2C2ctrl
jsr I2C2_busy_wait::nosep
lda f:I2C2io
rep #SHORT_A
.a16
and #$00FF
tay
lda #$0000
PUSHNEXT
eword
dword I2C2_FETCH,"I2C2@+"
jsr I2C2_busy_wait
.a8
lda #$04
bra I2C2_FETCH_ACK::dofetch
.a16
eword
dend
; and now for the system interface