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Code Issues Releases Wiki Activity

Adopted push/pop notation, added comments

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I explained why one nop seems unecessesary with some more comments.
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Clanmaster21 2019-10-18 18:53:56 +01:00 committed by GitHub
parent 370c3fa264
commit 176084d619
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1 changed files with 4 additions and 4 deletions
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8
kernel/sdc.asm
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@ -91,17 +91,17 @@ sdcWakeUp:
ld b, 10 ; 10 * 11 == 110 ld b, 10 ; 10 * 11 == 110
ld a, 0xff ld a, 0xff
.loop: .loop:
out (SDC_PORT_SPI), a out (SDC_PORT_SPI), a ;11 cycles
djnz .loop djnz .loop ;13 cycles
ret ret
; Initiate SPI exchange with the SD card. A is the data to send. Received data ; Initiate SPI exchange with the SD card. A is the data to send. Received data
; is placed in A. ; is placed in A.
sdcSendRecv: sdcSendRecv:
out (SDC_PORT_SPI), a out (SDC_PORT_SPI), a
push hl ; nop, pairs with pop later push hl ; nop, --> lvl 1
in a, (SDC_PORT_SPI) in a, (SDC_PORT_SPI)
pop hl ; nop, pairs with earlier push pop hl ; nop, <-- lvl 1
ret ret
sdcIdle: sdcIdle: