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avr: reduce register use in com2WaitForDataState1ms

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Martin Preuss
2023-04-22 12:12:19 +02:00
parent 3b44fb9c5b
commit 462515b566
1 changed files with 8 additions and 9 deletions
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17
avr/modules/com2/lowlevel.asm
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@@ -189,23 +189,22 @@ com2WaitForAttnHigh_done:
; --------------------------------------------------------------------------- ; ---------------------------------------------------------------------------
; com2WaitForDataState1ms ; com2WaitForDataState1ms
; ;
; Waits up to COM2_MAXWAIT_US loops for high ATTN line ; Waits up to 100ms for high DATA line
; IN: ; IN:
; - R16: state to wait for (00 for low, 0xff for high)
; OUT: ; OUT:
; - CFLAG: set if state reached, cleared otherwise ; - CFLAG: set if state reached, cleared otherwise
; REGS: R24 (R22) ; REGS: R17, R22
com2WaitForDataState1ms: com2WaitForDataState1ms:
ldi r24, 100 ldi r17, 100
com2WaitForDataState1ms_loop: com2WaitForDataState1ms_loop:
push r17 in r22, COM_PIN_DATA
in r17, COM_PIN_DATA eor r22, r16
eor r17, r16 andi r22, (1<<COM_PINNUM_DATA)
andi r17, (1<<COM_PINNUM_DATA)
pop r17
breq com2WaitForDataState1ms_stateReached breq com2WaitForDataState1ms_stateReached
Utils_WaitNanoSecs 10000, 0, r22 ; wait for 10us Utils_WaitNanoSecs 10000, 0, r22 ; wait for 10us
dec r24 dec r17
brne com2WaitForDataState1ms_loop brne com2WaitForDataState1ms_loop
clc clc
ret ret