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Make the initialization sequence more flexible 

According to the SD specification v2.00 we this is the right way to
initialize a card using the v1 protocol in a forward-compatible way.
pull/7774/head
LemonBoy 2017-08-14 16:46:38 +02:00
parent 2d247581c6
commit 52f5e0d41a
1 changed files with 8 additions and 5 deletions
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13
SDBlockDevice.cpp
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@ -274,14 +274,13 @@ int SDBlockDevice::_initialise_card()
return SD_BLOCK_DEVICE_ERROR_NO_DEVICE; return SD_BLOCK_DEVICE_ERROR_NO_DEVICE;
} }
// Send CMD8 // Send CMD8, if the card rejects the command then it's probably using the
if (BD_ERROR_OK != (status = _cmd8())) { // legacy protocol, or is a MMC, or just flat-out broken
status = _cmd8();
if (BD_ERROR_OK != status && SD_BLOCK_DEVICE_ERROR_UNSUPPORTED != status) {
return status; return status;
} }
// Disable CRC
status = _cmd(CMD59_CRC_ON_OFF, 0);
// Read OCR - CMD58 Response contains OCR register // Read OCR - CMD58 Response contains OCR register
if (BD_ERROR_OK != (status = _cmd(CMD58_READ_OCR, 0x0, 0x0, &response))) { if (BD_ERROR_OK != (status = _cmd(CMD58_READ_OCR, 0x0, 0x0, &response))) {
return status; return status;
@ -333,6 +332,10 @@ int SDBlockDevice::_initialise_card()
_card_type = SDCARD_V1; _card_type = SDCARD_V1;
debug_if(SD_DBG, "Card Initialized: Version 1.x Card\n"); debug_if(SD_DBG, "Card Initialized: Version 1.x Card\n");
} }
// Disable CRC
status = _cmd(CMD59_CRC_ON_OFF, 0);
return status; return status;
} }