Figure 6.1 Single Double Word Initialization Sequence Format - Renesas IDT 89HPES4T4 User Manual

IDT SMBus Interfaces
Notes
PES4T4 User Manual
During serial EEPROM initialization, the master SMBus interface begins reading bytes starting at serial
EEPROM address zero. These bytes are interpreted as configuration blocks and sequential reading of the
serial EEPROM continues until the end of a configuration done block is reached or the serial EEPROM
address rolls over from 0xFFFF to 0x0. All register initialization performed by the serial EEPROM is
performed in double word quantities.
There are three configuration block types that may be stored in the serial EEPROM. The first type is a
single double word initialization sequence. A double word initialization sequence occupies six bytes in the
serial EEPROM and is used to initialize a single double word quantity in the PES4T4. A single double word
initialization sequence consists of three fields and its format is shown in Figure 6.1. The CSR_SYSADDR
field contains the double word CSR system address of the double word to be initialized. The actual CSR
system address, which is a byte address, equals this value with two lower zero bits appended. The next
field is the TYPE field that indicates the type of the configuration block. For single double word initialization
sequence, this value is always 0x0. The final DATA field contains the double word initialization value.
Byte 0
Byte 1
Byte 2
Byte 3
Byte 4
Byte 5

Figure 6.1 Single Double Word Initialization Sequence Format

The second type of configuration block is the sequential double word initialization sequence. It is similar
to a single double word initialization sequence except that it contains a double word count that allows
multiple sequential double words to be initialized in one configuration block.
A sequential double word initialization sequence consists of four required fields and one to 65535
double word initialization data fields. The format of a sequential double word initialization sequence is
shown in Figure 6.2. The CSR_SYSADDR field contains the starting double word CSR system address to
be initialized. The next field is the TYPE field that indicates the type of the configuration block. For sequen-
tial double word initialization sequences, this value is always 0x1. The NUMDW field specifies the number
of double words initialized by the configuration block. This is followed by the number of DATA fields speci-
fied in the NUMDW field.
Serial EEPROM
24C128
24C256
24C512
Table 6.1 PES4T4 Compatible Serial EEPROMs
Bit Bit Bit Bit Bit
7 6 5 4 3
CSR_SYSADDR[7:0]
TYPE
CSR_SYSADDR[13:8]
0x0
DATA[7:0]
DATA[15:8]
DATA[23:16]
DATA[31:24]
6 - 2
Size
16 KB
32 KB
64 KB
Bit Bit Bit
2 1 0
February 1, 2011