IDT SMBus Interfaces
Slave SMBus Interface
PES12N3 User Manual
7 - 13
June 7, 2006
Notes
Sample Slave SMBus Operation
This section illustrates sample Slave SMBus operations. Shaded items are driven by the PES12N3’s
slave SMBus interface and non-shaded items are driven by an SMBus host.
Figure 7.8 CSR Register Read Using SMBus Block Write/Read Transactions with PEC Disabled
Bit
Field
Name
Type
1
1.
See Table Table 1.2 in Chapter 1 for a definition of these abbreviations.
Description
0
OP
RW
Serial EEPROM Operation. This field encodes the serial EEPROM
operation to be performed.
0 - Serial EEPROM write
1 - Serial EEPROM read
1
USA
RW
Use Specified Address. When this bit is set the serial EEPROM
SMBus address specified in the EEADDR is used instead of that
specified in the MSMBADDR field in the SMBUSSTS register.
2
Reserved
3
NAERR
RC
No Acknowledge Error. This bit is set if an unexpected NACK is
observed during a master SMBus transaction when accessing the
serial EEPROM. This bit has the same function as the NAERR bit in
the PA_SMBUSSTS register.
The setting of this bit may indicate the following: that the addressed
device does not exist on the SMBus (i.e., addressing error), data is
unavailable or the device is busy, an invalid command was detected
by the slave, invalid data was detected by the slave.
4
LAERR
RC
Lost Arbitration Error. This bit is set if the master SMBus interface
loses 16 consecutive arbitration attempts when accessing the serial
EEPROM. This bit has the same function as the LAERR bit in the
PA_SMBUSSTS register.
5
OTHERERR
RC
Other Error. This bit is set if a misplaced START or STOP condition is
detected by the master SMBus interface when accessing the serial
EEPROM. This bit has the same function as the OTHERERR bit in
the PA_SMBUSSTS register.
7:6
Reserved
0
Reserved. Must be zero
Table 7.12 Serial EEPROM Read or Write CMD Field Description
DATAUU
N
DATAUM
A
BYTCNT=7
A
ADDRL
CMD (status)
S
PES12N3 Slave
SMBus Address
Wr
A
A
BYTCNT=3
A
CMD=read
A
ADDRL
A
ADDRU
A
P
CCODE
START,END
S
PES12N3 Slave
SMBus Address
Wr
A
A
CCODE
START,END
S
PES12N3 Slave
SMBus Address
Rd
DATALM
DATALL
A
A
A
A
N
P
ADDRU
A
S
PES12N3 Slave
SMBus Address
Wr
A
N
CCODE
START,END
P
(PES12N3 not ready with data)
Summary of Contents for 89HPES12N3
Page 10: ...IDT Table of Contents PES12N3 User Manual iv June 7 2006 Notes...
Page 14: ...IDT List of Figures PES12N3 User Manual viii June 7 2006 Notes...
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Page 54: ...IDT Power Management Active State Power Management PES12N3 User Manual 5 4 June 7 2006 Notes...
Page 62: ...IDT Hot Plug and Hot Swap Hot Swap PES12N3 User Manual 6 8 June 7 2006 Notes...
Page 78: ...IDT SMBus Interfaces Slave SMBus Interface PES12N3 User Manual 7 16 June 7 2006 Notes...
Page 148: ...IDT Test and Debug SerDes Test Clock PES12N3 User Manual 10 6 June 7 2006...
Page 158: ...IDT JTAG Boundary Scan Usage Considerations PES12N3 User Manual 11 10 June 7 2006 Notes...