m35b32 STMicroelectronics, m35b32 Datasheet - Page 16

• Manufacturer Part Number: m35b32
• Description: 32 Kbit, 256-byte Page, Fast Program Eeprom Memory Accessed By Spi Bus Interface
• Manufacturer: STMicroelectronics

Instructions
6
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Instructions
All instructions, addresses and data are shifted in and out of the device, most significant bit
first.
Serial Data Input (D) is sampled on the first rising edge of Serial Clock (C) after Chip Select
(S) is driven low. Then, the one-byte instruction code must be shifted in to the device, most
significant bit first, on Serial Data Input (D), each bit being latched on the rising edges of
Serial Clock (C).
The instruction set is listed in
Every instruction sequence starts with a one-byte instruction code. Depending on the
instruction, this might be followed by address bytes, or by data bytes, or by both or none.
In the case of a Read Data Bytes (READ) or Read Status Register (RDSR) instruction, the
shifted-in instruction sequence is followed by a data-out sequence. Chip Select (S) can be
driven high after any bit of the data-out sequence is being shifted out.
In the case of a Page Write (PW), Page Program (PP), Page Erase (PE), Sector Erase (SE),
Write Enable (WREN) or Write Disable (WRDI) instruction, Chip Select (S) must be driven
high exactly at a byte boundary, otherwise the instruction is rejected, and is not executed.
That is, Chip Select (S) must driven high when the number of clock pulses after Chip Select
(S) being driven low is an exact multiple of eight.
All attempts to access the memory array during a Write cycle, Program cycle or Erase cycle
are ignored, and the internal Write cycle, Program cycle or Erase cycle continues
unaffected.
Table 2.
Instruction
WREN
WRSR
RDSR
READ
WRDI
RDID
PW
PP
PE
SE
Instruction set
Write Enable
Write Disable
Read Identification
Read Status Register
Write Status Register
Read Data Bytes
Page Write
Page Program
Page Erase
Sector Erase
Description
Table
Doc ID 18391 Rev 3
2.
One-byte instruction
0000 0110
0000 0100
1001 1111
0000 0101
0000 0001
0000 0011
0000 0010
0000 1010
1101 1011
1101 1000
code
DBh
D8h
9Fh
0Ah
06h
04h
05h
01h
03h
02h
Address
bytes
0
0
0
0
0
3
3
3
3
3
Dummy
bytes
0
0
0
0
0
0
0
0
0
0
1 to 256
1 to 256
M35B32
bytes
1 to 3
1 to
1 to
Data
0
0
1
0
0