40.8.1 SDHC SDMA System Address / Argument 2 Register

This register contains the physical system memory address used for SDMA transfers or the second argument for Auto CMD23.

Table 40-1. Register Bit Attribute Legend
Symbol	Description	Symbol	Description	Symbol	Description
R	Readable bit	HC	Cleared by Hardware	(Grey cell)	Unimplemented
W	Writable bit	HS	Set by Hardware	X	Bit is unknown at Reset
K	Write to clear	S	Software settable bit	—	—

Name:	SSAR
Offset:	0x00
Reset:	0x00000000
Property:	-


Bit	31	30	29	28	27	26	25	24
	ARG2[31:24]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	23	22	21	20	19	18	17	16
	ARG2[23:16]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	15	14	13	12	11	10	9	8
	ARG2[15:8]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0


Bit	7	6	5	4	3	2	1	0
	ARG2[7:0]
Access	R/W	R/W	R/W	R/W	R/W	R/W	R/W	R/W
Reset	0	0	0	0	0	0	0	0

Bits 31:0 – ARG2[31:0] SDMA System Address/Argument 2

The function of this bit field depends on the operational mode:

For a SDMA transfer, this field is the system memory address. When the peripheral stops an SDMA transfer, this field points to the system address of the next contiguous data position. This field can be accessed only if no transaction is executing (i.e., after a transaction has stopped). Read operations during transfers may return an invalid value. An interrupt can be generated to instruct the software to update this field. Writing the next system address of the next data position restarts the SDMA transfer.

When executing Auto CMD23, this field is used with Auto CMD23 to set a 32-bit block count value to the CMD23 argument. If Auto CMD23 is used with ADMA, the full 32-bit block count value can be used. If Auto CMD23 is used without ADMA, the available block count value is limited by SDHC_BCR. In this case, 65535 blocks is the maximum value.