Intel 21555 user manual CSR Address Map Sheet 2

List of Registers

Table 33. CSR Address Map (Sheet 2 of 5)

Byte
Offset	Register Name	Reset Value	Write Access	Read Access
(Hex)
	Downstream I/O Data and Upstream I/O
01B:018	Data Registers, page 145	Indeterminate	Primary	Primary
	Downstream I/O Data
	Downstream I/O Address and Upstream I/O
01F:01C	Address Registers, page 144	Indeterminate	Secondary	Y
	Upstream I/O Address
	Downstream I/O Data and Upstream I/O
023:020	Data Registers, page 145	Indeterminate	Secondary	Secondary
	Upstream I/O Data
024	I/O Own Bits Registers, page 145	00	N	Primary Read-
				0-to-set
	I/O Own Byte 0
				Secondary
025	I/O Own Byte 1	00	N
				Read-0-to-set
027:026	I/O CSR, page 146	0000	Y	Y
	I/O Own Control and Status
028	Lookup Table Offset Register, page 146	Indeterminate	Y	Y
	Look-up Table Offset
02B:029	Reserved	000	N	Y
02F:02C	Lookup Table Data Register, page 147	Indeterminate	Y	Y
	Look-up Table Data
033:030	I2O Outbound Post_List Status, page 165	00000000	N	Y
	I20 Outbound Post Status
	I2O Outbound Post_List Interrupt Mask,
037:034	page 165	00000004	Y	Y
	I20 Outbound Post Mask
03B:038	I2O Inbound Post_List Status, page 165	00000000	N	Y
	I20 Inbound Post Status
	I2O Inbound Post_List Interrupt Mask, page
03F:03C	166	00000004	Y	Y
	I20 Inbound Post Mask
043:040	I2O Inbound Queue, page 166	Indeterminate	Primary	Primary
	I20 Inbound Queue
047:044	I2O Outbound Queue, page 166	Indeterminate	Primary	Primary
	I20 Outbound Queue
	I2O Inbound Free_List Head Pointer, page
04B:048	167	Indeterminate	Y	Y
	I20 Inbound Free Head Pointer
	I2O Inbound Post_List Tail Pointer, page
04F:04C	167	Indeterminate	Y	Y
	I20 Inbound Post Tail Pointer
	I2O Outbound Free_List Tail Pointer, page
053:050	167	Indeterminate	Y	Y
	I20 Outbound Free Tail Pointer

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