5 class code and revision id register, 6 latency timer and class cache line size register – Texas Instruments Dual/Single Socket CardBus and UntraMedia Controller PCI7621 User Manual
Page 243
11−5
11.5 Class Code and Revision ID Register
The class code and revision ID register categorizes the base class, subclass, and programming interface of the
function. The base class is 01h, identifying the controller as a mass storage controller. The subclass is 80h, identifying
the function as other mass storage controller, and the programming interface is 00h. Furthermore, the TI chip revision
is indicated in the least significant byte (00h). See Table 11−4 for a complete description of the register contents.
Bit
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
Name
Class code and revision ID
Type
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
Default
0
0
0
0
0
0
0
1
1
0
0
0
0
0
0
0
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Class code and revision ID
Type
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
R
Default
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Register:
Class code and revision ID
Offset:
08h
Type:
Read-only
Default:
0180 0000h
Table 11−4. Class Code and Revision ID Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
31−24
BASECLASS
R
Base class. This field returns 01h when read, which classifies the function as a mass storage controller.
23−16
SUBCLASS
R
Subclass. This field returns 80h when read, which specifically classifies the function as other mass
storage controller.
15−8
PGMIF
R
Programming interface. This field returns 00h when read.
7−0
CHIPREV
R
Silicon revision. This field returns 00h when read, which indicates the silicon revision of the flash media
controller.
11.6 Latency Timer and Class Cache Line Size Register
The latency timer and class cache line size register is programmed by host BIOS to indicate system cache line size
and the latency timer associated with the flash media controller. See Table 11−5 for a complete description of the
register contents.
Bit
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
Name
Latency timer and class cache line size
Type
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
RW
Default
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Register:
Latency timer and class cache line size
Offset:
0Ch
Type:
Read/Write
Default:
0000h
Table 11−5. Latency Timer and Class Cache Line Size Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
15−8
LATENCY_TIMER
RW
PCI latency timer. The value in this register specifies the latency timer for the flash media controller,
in units of PCI clock cycles. When the flash media controller is a PCI bus initiator and asserts FRAME,
the latency timer begins counting from zero. If the latency timer expires before the flash media
transaction has terminated, then the flash media controller terminates the transaction when its GNT
is deasserted.
7−0
CACHELINE_SZ
RW
Cache line size. This value is used by the flash media controller during memory write and invalidate,
memory-read line, and memory-read multiple transactions.