IS25LD256C
DEVICE OPERATION (CONTINUED)
RDID COMMAND (READ PRODUCT
IDENTIFICATION) OPERATION
CE# goes high. The Device ID outputs repeatedly if
The Read Product Identification (RDID) instruction is continuously send the additional clock cycles on SCK
for reading out the old style of 8-bit Electronic
while CE# is at low.
Signature, whose values are shown as table of ID
Definitions. This is not same as RDID or JEDEC ID
instruction. It’s not recommended to use for new
Table 11. Product Identification
design. For new design, please use RDID or JEDEC ID
instruction.
Product Identification
Data
The RDES instruction code is followed by three dummy
First Byte
9Dh
bytes, each bit being latched-in on SI during the rising Manufacturer ID
edge of SCK. Then the Device ID is shifted out on SO
Second Byte
7Fh
with the MSB first, each bit been shifted out during the Device ID:
Device ID 1
Device ID 2
falling edge of SCK. The RDES instruction is ended by
IS25LD256C
02h
2Fh
Figure 3. Read Product Identification Sequence
CE#
01
78 9
31
38 39
46 47
54
SCK
INSTRUCTION 3 Dummy Bytes
SI
1010 1011b
HIGH IMPEDANCE
SO
Device ID1
Device ID1
Device ID1
Integrated Silicon Solution, Inc.- www.issi.com
11
Rev. A
09/11/2012