f4e16c0c12
Adds functions to wait for data to be read, and to read data form the sd card controller.
66 lines
1.1 KiB
ArmAsm
66 lines
1.1 KiB
ArmAsm
.include "io.inc65"
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.importzp sp, sreg, ptr1
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.export _sd_card_command
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.export _sd_card_resp
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.export _sd_card_read_byte
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.export _sd_card_wait_for_data
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.autoimport on
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.code
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; Send sd card command.
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; command is in A register, the args are on the stack
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; I think the order is high byte first?
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_sd_card_command:
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pha
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jsr popeax
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sta SD_ARG
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stx SD_ARG+1
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lda sreg
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sta SD_ARG+2
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lda sreg+1
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sta SD_ARG+3
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pla
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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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@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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_sd_card_read_byte:
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lda SD_DATA
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ldx #$00
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rts
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_sd_card_wait_for_data:
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pha
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@1: lda SD_CMD ; wait for status flag
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and #$02
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beq @1
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pla
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rts |