BCM1250/BCM1125/BCM1125H
User Manual
10/21/02
B r o a d c o m C o r p o r a t i o n
Page
418
Section 14: Serial Configuration Interface
Document
1250_1125-UM100CB-R
Table 297: SMBus Start and Command Registers Extended Mode
smb_start_0 -
00_1006_0040
smb_start_1 -
00_1006_0048
Bits
Name
Default
Description
6:0
smb_addr
7'h0
The serial interface address. These 7 bits are used to form the address byte that
is sent across the serial interface.
7
smb_qdata
1'b0
Bit of data to send as R/W bit in a Quick Command. Ignored, write as zero for all
other commands.
10:8
smb_datafmt
3'h0
Data Format
Value Data Transfer
000
Data[7:0].
001
Data[7:0], Data[15:8]
010
Data[7:0], Data[15:8], Xtra[7:0]
011
Data[7:0], Data[15:8], Xtra[7:0], Xtra[15:8]
100
No data.
101
Only valid for read transactions
Cmd[7:0], Data[7:0], Data[15:8], Xtra[7:0],Xtra[15:8]
110
Only valid for read transactions
Cmd[7:0], Cmd[15:8], Data[7:0], Data[15:8], Xtra[7:0], Xtra[15:8]
111
Reserved
12:11
smb_afmt
2'h0
Address/Command Format
Value Address/Command Transfer
00
Only valid for read transactions: No Address.
01
Slave Address Only
10
Slave Address then Cmd[7:0]
11
Slave Address then Cmd[7:0], Cmd[15:0]
13
smb_dir
1'b0
Set to 0 for a write transaction, 1 for a read transaction.
14
extend
1'b1
This bit should be set to one for extended protocol mode.
15
smb_pec
1'b0
Set to modify the transfer type to use Packet Error Checking as defined in the
SMBus 1.1 specification. Zero for regular operation.
63:16
notimp
48'bx
Not Implemented.