Karthikeyan,
DSPI read:
- Check status (sr & 0x0000F000), continue if >= 4
- Write 0x800n0003 to pop register (0xfc05c038) where n is chipsel (1 <<
chipsel), 3 is perform read (AT25080A does not have fast read feature)
- dummy read
- write 0x800n00xx to popr, address byte 2
- dummy read
- write 0x800n00xx to popr, address byte 1
- dummy read
- write 0x800n00xx to popr, address byte 0
- dummy read
- write 0x800n0000 to popr, ready for read
- read a byte
Hope this help.
[snip - assembly]
move.l #0xFC05C034, %a2 /* dtfr */
move.l #0xFC05C03B, %a3 /* drfr */
move.l #0x2a000, %d5
move.l #(TEXT_BASE), %a4
move.l #0xFC05C02C, %a1 /* dspi status */
/* Issue commands and address */
move.l #0x80020003, %d2 /* Fast Read Cmd */
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
move.l #0x80020000, %d2 /* Address byte 2 */
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
move.l #0x80020000, %d2 /* Address byte 1 */
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
move.l #0x80020003, %d2 /* Address byte 0 */
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
/* Transfer u-boot from serial flash to memory */
asm_dspi_rd_loop2:
move.l #0x80020000, %d2
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
move.b %d1, (%a4) /* read, copy to dst */
add.l #1, %a4 /* inc dst by 1 */
sub.l #1, %d5 /* dec cnt by 1 */
bne asm_dspi_rd_loop2
move.l #0x00020000, %d2 /* Terminate */
jsr asm_dspi_wr_status
jsr asm_dspi_rd_status
asm_dspi_wr_status:
move.l (%a1), %d0 /* status */
and.l #0x0000F000, %d0
cmp.l #0x00003000, %d0
bgt asm_dspi_wr_status
move.l %d2, (%a2)
rts
asm_dspi_rd_status:
move.l (%a1), %d0 /* status */
and.l #0x000000F0, %d0
lsr.l #4, %d0
cmp.l #0, %d0
beq asm_dspi_rd_status
move.b (%a3), %d1
rts
[snip - c]
do {
dspi_tx(chipsel, 0x80, SER_RDSR);
dspi_rx();
dspi_tx(chipsel, 0x00, 0);
temp = dspi_rx();
} while (temp & 0x01);
dspi_tx(chipsel, 0x80, SER_READ);
dspi_rx();
dspi_tx(chipsel, 0x80, 0);
dspi_rx();
dspi_tx(chipsel, 0x80, 0);
dspi_rx();
dspi_tx(chipsel, 0x80, 0);
dspi_rx();
for (i = 0; i < bytes; i++) {
dspi_tx(chipsel, 0x80, 0);
buf[i] = dspi_rx();
}
dspi_tx(chipsel, 0x00, 0);
dspi_rx();
for (i = 0; i < bytes; i++) {
if ((i % 16) == 0)
printf("\n");
printf("%02x ", buf[i]);
}
Regards,
TsiChung
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