7682dffe3c
Seems to work, when you run the test program it resets the card and sends the voltage and test pattern, and it does receive a response from the card.
151 lines
2.5 KiB
ArmAsm
151 lines
2.5 KiB
ArmAsm
.importzp sp, sreg, ptr1, tmp1, tmp2, tmp3, tmp4
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.export _sd_card_command
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.export _sd_card_resp
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.autoimport on
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.code
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SD_ARG = $efd8
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SD_CMD = $efdc
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SD_DATA = $efdd
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_resp = $10
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main:
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@cmd0:
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jsr stztmp ; arg = 0
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lda #$00 ; cmd = 0
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jsr _sd_card_command
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nop ; no resp, so need to wait for cmd to finish
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lda #$18
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@delay: dec
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bne @delay
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@cmd8:
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lda #$aa
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sta tmp1
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inc tmp2 ; arg = 000001aa
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lda #$08 ; cmd = 8
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jsr _sd_card_command
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lda #<_resp
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ldx #>_resp
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jsr _sd_card_resp_timeout
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lda _resp
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beq @cmd8
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end:
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wai
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bra end
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stztmp:
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stz tmp1
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stz tmp2
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stz tmp3
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stz tmp4
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rts
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; Send sd card command.
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; command is in A register, the args are in tmp1-4 le
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_sd_card_command:
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pha ; store cmd
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lda tmp1 ; write args
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sta SD_ARG
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lda tmp2
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sta SD_ARG+1
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lda tmp3
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sta SD_ARG+2
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lda tmp4
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sta SD_ARG+3
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pla ; write cmd
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sta SD_CMD
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rts
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; void sd_card_resp(uint32_t* resp);
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_sd_card_resp:
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phy
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sta ptr1 ; store pointer
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stx ptr1+1
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lda #$0
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ldy #$0
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sta (ptr1),y
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iny
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sta (ptr1),y
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iny
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sta (ptr1),y
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iny
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sta (ptr1),y
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@1: lda SD_CMD ; wait for status flag
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and #$01
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beq @1
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lda SD_ARG
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ldy #$0
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sta (ptr1),y
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lda SD_ARG+1
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iny
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sta (ptr1),y
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lda SD_ARG+2
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iny
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sta (ptr1),y
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lda SD_ARG+3
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iny
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sta (ptr1),y
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ply
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rts
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; int sd_card_resp_timeout(uint32_t* resp);
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_sd_card_resp_timeout:
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phy
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sta ptr1 ; store pointer
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stx ptr1+1
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lda #$0
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ldy #$0
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sta (ptr1),y
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iny
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sta (ptr1),y
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iny
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sta (ptr1),y
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iny
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sta (ptr1),y
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ldy #$12
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@1: dey
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beq @timeout
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lda SD_CMD ; wait for status flag
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and #$01
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beq @1
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lda SD_ARG
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ldy #$0
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sta (ptr1),y
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lda SD_ARG+1
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iny
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sta (ptr1),y
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lda SD_ARG+2
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iny
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sta (ptr1),y
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lda SD_ARG+3
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iny
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sta (ptr1),y
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ply
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lda #$00
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ldx #$00
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rts
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@timeout:
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ply
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lda #$ff
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ldx #$ff
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rts
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.segment "VECTORS"
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.addr main
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.addr main
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.addr main
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