K60P100M100SF2RM Datasheet, PDF (1660/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Initialization/application of SDHC
if (HS_TIMING is not 0) report the function switch failed and return;
change clock divisor value or configure the system clock feeding into eSDHC to generate the
card_clk of the desired value below 20MHz;
(data transactions like normal peers)
}
52.6.4.4 Set MMC bus width
change_mmc_bus_width(void)
{
send CMD9 to get CSD value of MMC;
check if the value of SPEC_VER field is 4 or above;
if (SPEC_VER value is less than 4) report the MMC does not support multiple bit width and
return;
send CMD6 with argument 0x3B70x00; (8-bit, x=2; 4-bit, x=1; 1-bit, x=0)
send CMD13 to wait card ready (busy line released);
(data transactions like normal peers)
}
52.6.5 ADMA operation
This section presents code examples for ADMA operation.
52.6.5.1 ADMA1 operation
Set_adma1_descriptor
{
if (to start data transfer) {
// Make sure the address is 4KB align.
Set 'Set' type descriptor;
{
Set Act bits to 01;
Set [31:12] bits data length (byte unit);
}
Set 'Tran' type descriptor;
{
Set Act bits to 10;
Set [31:12] bits address (4KB align);
}
}
else if (to fetch descriptor at non-continuous address) {
Set Act bits to 11;
Set [31:12] bits the next descriptor address (4KB align);
}
else { // other types of descriptor
Set Act bits accordingly
}
if (this descriptor is the last one) {
Set End bit to 1;
}
if (to generate interrupt for this descriptor) {
Set Int bit to 1;
}
Set Valid bit to 1;
}
1660
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.