Renesas 89HPES24T3G2ZBAL, Руководство пользователя

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IDT SMBus Interfaces
PES24T3G2 User Manual 5 - 15 February 22, 2012
Notes
address and upper 6-bit doubleword system address, respectively. For example, use ADDRU = x00 and
ADDRL = 0x00 to access system address 0x00000 (port 0’s Vendor/Device ID register). Use ADDRU = x00
and ADDRL = 0x01 to access system address 0x00004 (port 0’s Command/Status register).
The format of the CMD field is shown in Figure 5.6 and described in Table 5.12.
Figure 5.6 CSR Register Read or Write CMD Field Format
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 performed.
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 transac-
tions. 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 indi-
cate the number of following bytes (including status).
2 CMD Command. This field contains information related to the serial EEPROM transaction
Table 5.13 Serial EEPROM Read or Write Operation Byte Sequence (Part 1 of 2)
Bit
6
Bit
7
Bit
0
Bit
1
Bit
2
Bit
3
Bit
4
Bit
5
BELL BELM WERR BEUM BEUU OP RERR 0