IDT 89HPES12T3G2, Preliminary User'S Manual

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IDT SMBus Interfaces
PES12T3G2 User Manual 5 - 14 January 28, 2013
Notes
Serial EEPROM Read or Write Operation
Table 5.12 indicates the sequence of data as it is presented on the slave SMBus following the byte
address of the Slave SMBus interface.
Bit
Field
Name Type Description
0 BELL Read/Write Byte Enable Lower. When set, the byte enable for bits [7:0] of the
data word is enabled.
1 BELM Read/Write Byte Enable Lower Middle. When set, the byte enable for bits [15:8]
of the data word is enabled.
2 BEUM Read/Write Byte Enable Upper Middle. When set, the byte enable for bits
[23:16] of the data word is enabled.
3 BEUU Read/Write Byte Enable Upper. When set, the byte enable for bits [31:24] of the
data word is enabled.
4 OP Read/Write CSR Operation. This field encodes the CSR operation to be per-
formed.
0 - CSR write
1 - CSR read
5 0 0 Reserved. Must be zero
6 RERR Read-Only
and Clear
Read Error. This bit is set if the last CSR read SMBus transaction was
not claimed by a device. Success indicates that the transaction was
claimed and not that the operation completed without error.
7 WERR Read-Only
and Clear
Write Error. This bit is set if the last CSR write SMBus transaction was
not claimed by a device. Success indicates that the transaction was
claimed and not that the operation completed without error.
Table 5.12 CSR Register Read or Write CMD Field Description
Byte
Position
Field
Name Description
0 CCODE Command Code. Slave Command Code field described in Table
5.10.
1 BYTCNT Byte Count. The byte count field is only transmitted for block type
SMBus transactions. SMBus word and byte accesses to not contain
this field. The byte count field indicates the number of bytes following
the byte count field when performing a write or setting up for a read.
The byte count field is also used when returning data to indicate the
number of following bytes (including status).
2 CMD Command. This field contains information related to the serial
EEPROM transaction
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.
Table 5.13 Serial EEPROM Read or Write Operation Byte Sequence