RM0082
RS_SDIO controller
Doc ID 018672 Rev 1
697/844
32.7 Register
description
This section describes the register of SDIO.
32.7.1 SDMASysAddr
register
This register contains the system memory address for a DMA transfer. When the Host
Controller (HC) stops a DMA transfer, this register shall point to the system address of the
next contiguous data position. It can be accessed only if no transaction is executing (that is
after a transaction has stopped). Read operations during transfer return an invalid value.
The Host Driver (HD) shall initialize this register before starting a DMA transaction.
After DMA has stopped, the next system address of the next contiguous data position can
be read from this register.
The DMA transfer waits at every boundary specified by the Host DMA Buffer Size in the
Block Size register. The Host Controller generates DMA Interrupt to request to update this
register. The HD sets the next system address of the next data position to this register.
When most upper byte of this register (0x003) is written, the HC restart the DMA transfer.
When restarting DMA by the resume command or by setting Continue Request in the Block
Gap Control register, the HC shall start at the next contiguous address stored here in the
System Address register.
The SDMASysAddr bit assignments are given in
32.7.2 BLKSize
register
The BLKSize bit assignments are given in
.
Table 617.
SDMASysAddr register bit assignments
Bit
Name
Reset
value
Type
Description
[31:00]
SDMASysAd
dr
32’h0
RW
This register contains the system memory address
for a DMA transfer.
Table 618.
BLKSize register bit assignments
Bit
Name
Reset
value
Type
Description
[15]
TBLKSize12
1’h0
Rsvd
Transfer Block Size 12th bit. This bit is added to
support 4Kb Data block transfer.