Renesas 89HPES24T3G2ZBAL, User Manual

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IDT SMBus Interfaces
PES24T3G2 User Manual 5 - 16 February 22, 2012
Notes
The format of the CMD field is shown in Figure 5.7 and described in Table 5.14.
Figure 5.7 Serial EEPROM Read or Write CMD Field Format
3 EEADDR Serial EEPROM Address. This field specifies the address of the Serial EEPROM
on the Master SMBus when the USA bit is set in the CMD field. Bit zero must be
zero and thus the 7-bit address must be left justified.
4 ADDRL Address Low. Lower 8-bits of the Serial EEPROM byte to access.
5 ADDRU Address Upper. Upper 8-bits of the Serial EEPROM byte to access.
6 DATA Data. Serial EEPROM value read or to be written.
Bit
Field
Name Type
1
Description
0 OP RW Serial EEPROM Operation. This field encodes the serial EEPROM oper-
ation 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
ADDR field in the EEPROMINTF register.
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 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 SMBUSSTS reg-
ister.
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 SMBUSSTS reg-
ister.
Table 5.14 Serial EEPROM Read or Write CMD Field Description
Byte
Position
Field
Name Description
Table 5.13 Serial EEPROM Read or Write Operation Byte Sequence (Part 2 of 2)
Bit
6
Bit
7
Bit
0
Bit
1
Bit
2
Bit
3
Bit
4
Bit
5
OP USA 0 NAERR LAERR OTHERERR 0