EN25P05
Read Identification (RDID)(9Fh)
The Read Identification (RDID) instruction allows the 8-bit manufacturer identification to be read,
followed by two bytes of device identification. The device identification indicates the memory type in
the first byte , and the memory capacity of the device in the second byte .
Any Read Identification (RDID) instruction while an Erase or Program cycle is in progress, is not
decoded, and has no effect on the cycle that is in progress. The Read Identification (RDID)
instruction should not be issued while the device is in Deep Power down mode.
The device is first selected by driving Chip Select Low. Then, the 8-bit instruction code for the
instruction is shifted in. This is followed by the 24-bit device identification, stored in the memory,
being shifted out on Serial Data Output , each bit being shifted out during the falling edge of Serial
Clock . The instruction sequence is shown in Figure 18. The Read Identification (RDID) instruction is
terminated by driving Chip Select High at any time during data output.
When Chip Select is driven High, the device is put in the Standby Power mode. Once in the Standby
Power mode, the device waits to be selected, so that it can receive, decode and execute instructions.
Figure 18. Read Identification (RDID)
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc., www.essi.com.tw
19
Rev. C, Issue Date: 2008/01/17
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
