12. Serial EEPROM > Functional Timing
105
PEB383 User Manual
July 25, 2011
Integrated Device Technology, Inc.
Confidential - NDA Required
12.4
Functional Timing
The EEPROM Controller outputs the data on the SR_DIN signal on every negative edge of the
SR_CLK clock. The external EEPROM samples this output on every positive edge of SR_CLK.
Similarly, the external EEPROM outputs the data on SR_DOUT on every negative edge of SR_CLK,
while the Controller samples it on every positive edge of the clock.
For read or write instructions in support of addresses greater than 0xFFH (in 9-bit addressing mode),
the 8th bit of the address is transmitted in place of the third bit of the opcode of that instruction; thus,
the address phase consists of 8 clock cycles. The timing for different instructions of the EEPROM
Controller are provided in the following figures.
Figure 31: 9-bit EEPROM Read Timing
FFFEh
CSR register r Data [23:16]
Any number
FFFFh
CSR register r Data [31:24]
Any number
Table 31: EEPROM Image
(Continued)
Serial EEPROM
Location
Description
Value
SR_CSn
SR_CLK
SR_DIN
SR_DOUT
Opcode
Address
Data
High-Z
SR_CSn
SR_CLK
SR_CLK
SR_DIN
SR_DIN
SR_DOUT
SR_DOUT
Opcode
Address
Data
High-Z