cs5535 National Semiconductor Corporation, cs5535 Datasheet - Page 358

• Manufacturer Part Number: cs5535
• Description: Geode Cs5535 Companion Multi-function South Bridge
• Manufacturer: National Semiconductor Corporation

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SMB Controller Register Descriptions
5.11.1.5
SMB I/O Offset
Type
Reset Value
Bit
Bit
6:0
1
0
7
SAEN
7
SMB Address (SMB_ADDR)
Name
STOP
START
Name
SAEN
SMBADDR
04h
R/W
00h
6
Description
Stop.
0: Automatically cleared after Stop issued.
1: Setting this bit in master mode generates a Stop condition to complete or abort cur-
Start. Set this bit only when in master mode or when requesting master mode.
0: Cleared after Start condition sent or Bus Error (BER (SMB I/O Offset 01h[5]) = 1)
1: Single or repeated Start condition generated on the SMB. If the device is not the
Description
Slave Enable.
0: SMB does not check for an address match with address field.
1: Address field holds a valid address and enables the match of ADDR to an incoming
Device address (SMB Own Address). These bits hold the 7-bit device address. When
in slave mode, the first 7 bits received after a Start condition are compared with this
field (first bit received is compared with bit 6, and the last bit with bit 0). If the address
field matches the received data and SAEN (bit 7) is 1, a match is declared.
rent message transfer.
detected.
active master of the bus (MASTER (SMB I/O Offset 01h[1]) = 0), setting START gen-
erates a Start condition when the SMB becomes free (BB (SMB I/O Offset 02h[1]) =
0). An address transmission sequence should then be performed.
If the device is the active master of the bus (MASTER = 1), setting START and then
writing to SMBSDA generates a Start condition. If a transmission is already in
progress, a repeated Start condition is generated. This condition can be used to
switch the direction of the data flow between the master and the slave, or to choose
another slave device without separating them with a Stop condition.
address byte.
5
SMB_CTRL1 Bit Descriptions
SMB_ADDR Bit Descriptions
SMB_ADDR Register Map
4
(Continued)
358
SMBADDR
3
2
1
Revision 0.8
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