AT25320B ATMEL [ATMEL Corporation], AT25320B Datasheet - Page 7

• Manufacturer Part Number: AT25320B
• Description: SPI Serial EEPROMs 32K (4096 x 8) 64K (8192 x 8)
• Manufacturer: ATMEL [ATMEL Corporation]

2. Functional Description
8535B–SEEPR–7/08
operation to the status register. The WP pin function is blocked when the WPEN bit in the status
register is “0”. This will allow the user to install the AT25320B/640B in a system with the WP pin
tied to ground and still be able to write to the status register. All WP pin functions are enabled
when the WPEN bit is set to “1”.
Figure 1-1.
The AT25320B/640B is designed to interface directly with the synchronous serial peripheral
interface (SPI) of the 6805 and 68HC11 series of microcontrollers.
The AT25320B/640B utilizes an 8-bit instruction register. The list of instructions and their opera-
tion codes are contained in
the MSB first and start with a high-to-low CS transition.
Table 2-1.
Instruction Name
WREN
WRDI
RDSR
SPI Serial Interface
Instruction Set for the AT25320B/640B
Instruction Format
0000 X110
0000 X100
0000 X101
Table
2-1. All instructions, addresses, and data are transferred with
Operation
Set Write Enable Latch
Reset Write Enable Latch
Read Status Register
AT25320B/640B
AT25320B/640B
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