AT45DB321E datasheet(16/80 Pages) RENESAS

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DS-AT45DB321E-8784 Rev. N

Page 16

9/1/23

AT45DB321E Datasheet

Program and Erase Commands

7.1

Buffer Write

Using the Buffer Write command allows data clocked in from the SI pin to be written directly into either one of the

SRAM data buffers.

To load data into a buffer using the standard DataFlash buffer size (528 bytes), an opcode of 84h for Buffer 1 or

87h for Buffer 2 must be clocked into the device followed by three address bytes comprised of 14 dummy bits and

10 buffer address bits (BFA9 - BFA0). The 10 buffer address bits specify the first byte in the buffer to be written.

To load data into a buffer using the binary buffer size (512 bytes), an opcode of 84h for Buffer 1 or 87h for Buffer 2,

must be clocked into the device followed by 15 dummy bits and nine buffer address bits (BFA8 - BFA0). The nine

buffer address bits specify the first byte in the buffer to be written.

After the last address byte has been clocked into the device, data can then be clocked in on subsequent clock

cycles. If the end of the data buffer is reached, the device wraps around back to the beginning of the buffer. Data

continues to be loaded into the buffer until a low-to-high transition is detected on the CS pin.

7.2

Buffer to Main Memory Page Program with Built-In Erase

The Buffer to Main Memory Page Program with Built-In Erase command allows data that is stored in one of the

SRAM buffers to be written into an erased or programmed page in the main memory array. It is not necessary to

pre-erase the page in main memory to be written because this command automatically erases the selected page

prior to the program cycle.

To perform a Buffer to Main Memory Page Program with Built-In Erase using the standard DataFlash page size

(528 bytes), an opcode of 83h for Buffer 1 or 86h for Buffer 2 must be clocked into the device followed by three

address bytes comprised of one dummy bit, 13 page address bits (PA12 - PA0) that specify the page in the main

memory to be written, and 10 dummy bits.

To perform a Buffer to Main Memory Page Program with Built-In Erase using the binary page size (512 bytes), an

opcode of 83h for Buffer 1 or 86h for Buffer 2 must be clocked into the device followed by three address bytes

comprised of two dummy bits, 13 page address bits (A21 - A9) that specify the page in the main memory to be

written, and nine dummy bits.

When a low-to-high transition occurs on the CS pin, the device first erases the selected page in main memory (the

erased state is a Logic 1) and then program the data stored in the appropriate buffer into that same page in main

memory. Both the erasing and the programming of the page are internally self-timed and takes place in a

maximum time of tEP. During this time, the RDY/BUSY bit in the Status Register indicates that the device is busy.

The device also incorporates an intelligent erase and program algorithm that can detect when a byte location fails

to erase or program properly. If an erase or programming error arises, it is indicated by the EPE bit in the Status

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