M95020-R datasheet(25/46 Pages) STMICROELECTRONICS

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M950x0-W M950x0-R M950x0-DF

Instructions

6.7

Read Identification Page (available only in M95040-D device)

The Read Identification Page (RDID) instruction is used to read the Identification Page

(additional page of 16 bytes which can be written and later permanently locked in Read-only

mode).

The Chip Select (S) signal is first driven low, the bits of the instruction byte and address

bytes are then shifted in (MSB first) on Serial Data input (D). Address bit A7 must be 0 and

the other address bits are Don't Care except the lower address bits [A3:A0] (it might be

easier to define these bits as 0, as shown in Table 5). Data is then shifted/clocked out (MSB

first) on Serial Data output (Q).

The first byte addressed can be any byte within the identification page.

If Chip Select (S) continues to be driven low, the internal address register is automatically

incremented and the byte of data at the new address is shifted out.

Note that there is no roll over feature in the Identification Page. The address of bytes to read

must not exceed the page boundary.

The read cycle is terminated by driving Chip Select (S) high. The rising edge of the Chip

Select (S) signal can occur at any time when the data bits are shifted out.

The instruction is not accepted, and is not executed, if a Write cycle is currently in progress.

Figure 14. Read Identification Page sequence

M95020-R Datasheet(PDF) 25 Page - STMicroelectronics