s-25a080a Seiko Instruments Inc., s-25a080a Datasheet - Page 20

• Manufacturer Part Number: s-25a080a
• Description: 25?c Operation Spi Serial E2prom For Automotive Electric Component
• Manufacturer: Seiko Instruments Inc.

20
SCK
125°C OPERATION SPI SERIAL E
S-25A080A/160A/320A
WP
SO
CS
7. Write memory data (Write)
SI
Remark In the S-25A080A, the higher addresses A15 to A10 = Don’t care.
Figure 15 shows the timing chart when inputting 1-byte data. Input the instruction code, the address and data from
serial data input (SI) after inputting “L” to the chip select ( CS ). To start Write (t
inputting data or before inputting a rising of the next serial clock. Bit WIP and WEL are reset to “0” when Write has
completed.
The S-25A080A/160A/320A can Page Write of 32 bytes. Its function to transmit data is as same as Byte Write
basically, but it operates Page Write by receiving sequential 8-bit Write data as much data as page size has. Input the
instruction code, the address and data from serial data input (SI) after inputting “L” in CS , as the Write operation
(page) shown in Figure 15. Input the next data while keeping CS in “L”. After that, repeat inputting data of 8-bit
sequentially. At the end, by setting CS to “H”, the Write operation starts (t
5 of the lower bits in the address are automatically incremented every time when receiving Write data of 8-bit. Thus,
even if Write data exceeds 32 bytes, the higher bits in the address do not change. And 5 of lower bits in the address
roll over so that Write data which is previously input is overwritten.
These are cases when the Write instruction is not accepted or operated.
• Bit WEL is not set to “1” (not set to “1” beforehand immediately before the Write instruction)
• During Write
• The address to be written is in the protect area by BP1 and BP0.
To cancel the Write instruction, input the clock different from a specified value (n = 24+m × 8 clock) while CS is in “L”.
In the S-25A160A, the higher addresses A15 to A11 = Don’t care.
In the S-25A320A, the higher addresses A15 to A12 = Don’t care.
1
2
3
Instruction
4
High-Z
5
6
7
Figure 15 Write Operation (1 byte)
8
A15 A14 A13
2
High / Low
PROM FOR AUTOMOTIVE ELECTRIC COMPONENT
9
Seiko Instruments Inc.
10
16-bit Address
11
A3
21
A2
22
A1
23
A0
24
PR
D7
).
25
PR
D6
26
), set the chip select ( CS ) to “H” after
D5
27
Data Byte 1
D4
28
D3
29
D2
30
D1
31
Rev.1.0
D0
32
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