M25P64-VMF6TPBA Datasheet, PDF (25/55 Pages) Numonyx B.V – 64 Mbit, low voltage, Serial Flash memory with 75 MHz SPI bus interface

M25P64
Instructions
6.3
Read Identification (RDID)
The read identification (RDID) instruction allows to read the device identification data:
„ Manufacturer identification (1 byte)
„ Device identification (2 bytes)
„ A unique ID code (UID) (17 bytes, of which 16 available upon customer request).⁽¹⁾
The manufacturer identification is assigned by JEDEC, and has the value 20h for Numonyx.
The device identification is assigned by the device manufacturer, and indicates the memory
type in the first byte (20h), and the memory capacity of the device in the second byte (17h).
The UID contains the length of the following data in the first byte (set to 10h) and 16 bytes of
the optional customized factory data (CFD) content. The CFD bytes are read-only and can
be programmed with customers data upon their demand. If the customers do not make
requests, the devices are shipped with all the CFD bytes programmed to zero (00h).
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 (S) Low. Then, the 8-bit instruction code
for the instruction is shifted in. After this, the 24-bit device identification, stored in the
memory, the 8-bit CFD length followed by 16 bytes of CFD content will be shifted out on
serial data output (DQ1). Each bit is shifted out during the falling edge of Serial Clock (C).
The instruction sequence is shown in Figure 10.
The read identification (RDID) instruction is terminated by driving Chip Select (S) High at
any time during data output. When Chip Select (S) 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.
Table 5. Read identification (RDID) data-out sequence
Manufacturer identification
Device identification
Memory type
Memory capacity
20h
20h
17h
UID
CFD length
10h
CFD content
16 bytes
1. The UID feature is available only for process technology T9HX devices, identified by process identification digit
"4" in the device marking.
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