
OHCI Registers
156
September 2005
SCPS110
8.1
OHCI Version Register
The OHCI version register indicates the OHCI version support and whether or not the serial EEPROM is
present. See Table 82 for a complete description of the register contents.
OHCI register offset:
00h
Register type:
Read-only
Default value:
0X01 0010h
BIT NUMBER
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RESET STATE
0
X
0
1
BIT NUMBER
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESET STATE
0
1
0
Table 82. OHCI Version Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
3125
RSVD
R
Reserved. Bits 3125 return 000 0000b when read.
24
GUID_ROM
RU
The controller sets bit 24 to 1b if the serial EEPROM is detected. If the serial EEPROM is present, then
the Bus_Info_Block is automatically loaded on system (hardware) reset. The default value for this bit is
0b.
2316
version
R
Major version of the OHCI. The controller is compliant with the 1394 Open Host Controller Interface
Specification (Release 1.1); thus, this field reads 01h.
158
RSVD
R
Reserved. Bits 158 return 00h when read.
70
revision
R
Minor version of the OHCI. The controller is compliant with the 1394 Open Host Controller Interface
Specification (Release 1.1); thus, this field reads 10h.
This bit is cleared only by the assertion of GRST.
8.2
GUID ROM Register
The GUID ROM register accesses the serial EEPROM, and is only applicable if bit 24 (GUID_ROM) in the
OHCI version register at OHCI offset 00h (see Section 8.1) is set to 1b. See Table 83 for a complete
description of the register contents.
OHCI register offset:
04h
Register type:
Read/Set/Update, Read/Update, Read-only
Default value:
00XX 0000h
BIT NUMBER
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
RESET STATE
0
X
BIT NUMBER
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
RESET STATE
0
Table 83. GUID ROM Register Description
BIT
FIELD NAME
TYPE
DESCRIPTION
31
addrReset
RSU
Software sets bit 31 to 1b to reset the GUID ROM address to 0. When the controller completes the reset,
it clears this bit. The controller does not automatically fill bits 2316 (rdData field) with the 0th byte.
3026
RSVD
R
Reserved. Bits 3026 return 00000b when read.
25
rdStart
RSU
A read of the currently addressed byte is started when bit 25 is set to 1b. This bit is automatically cleared
when the controller completes the read of the currently addressed GUID ROM byte.
24
RSVD
R
Reserved. Bit 24 returns 0b when read.
2316
rdData
RU
This field contains the data read from the GUID ROM.
158
RSVD
R
Reserved. Bits 158 return 00h when read.
70
miniROM
R
The miniROM field defaults to 00h indicating that no mini-ROM is implemented. If an EEPROM is
implemented, then all 8 bits of this miniROM field are downloaded from EEPROM word offset 28h. For this
device, the miniROM field must be greater than 61h to indicate a valid miniROM offset into the EEPROM.