AT45DB321E datasheet(18/80 Pages) RENESAS

18 / 80 page

DS-AT45DB321E-8784 Rev. N

Page 18

9/1/23

AT45DB321E Datasheet

7.5

Main Memory Byte/Page Program through Buffer 1 without Built-In Erase

The Main Memory Byte/Page Program through Buffer 1 without Built-In Erase command combines both the Buffer

Write and Buffer to Main Memory Program without Built-In Erase operations to allow any number of bytes (1 to

512/528 bytes) to be programmed directly into previously erased locations in the main memory array. With the

Main Memory Byte/Page Program through Buffer 1 without Built-In Erase command, data is first clocked into

Buffer 1, and then only the bytes clocked into the buffer are programmed into the pre-erased byte locations in

main memory. Multiple bytes up to the page size can be entered with one command sequence.

To perform a Main Memory Byte/Page Program through Buffer 1 using the standard DataFlash page size (528

bytes), an opcode of 02h must first 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

buffer address bits (BFA9 - BFA0) that select the first byte in the buffer to be written. After all address bytes are

clocked in, the device takes data from the input pin (SI) and store it in Buffer 1. Any number of bytes (1 to 528) can

be entered. If the end of the buffer is reached, then the device wraps around back to the beginning of the buffer.

To perform a Main Memory Byte/Page Program through Buffer 1 using the binary page size (512 bytes), an

opcode of 02h for Buffer 1 using must first 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 buffer address bits (BFA8 - BFA0) that selects the first byte in the buffer to be written. After all address bytes

are clocked in, the device takes data from the input pin (SI) and store it in Buffer 1. Any number of bytes (1 to 512)

can be entered. If the end of the buffer is reached, then the device wraps around back to the beginning of the

buffer. When using the binary page size, the page and buffer address bits correspond to a 22-bit logical address

(A21-A0) in the main memory.

After all data bytes have been clocked into the device, a low-to-high transition on the CS pin starts the program

operation in which the device programs the data stored in Buffer 1 into the main memory array. Only the data

bytes that were clocked into the device are programmed into the main memory.

Example: If only two data bytes were clocked into the device, then only two bytes are programmed into main

memory and the remaining bytes in the memory page remain in their previous state.

The CS pin must be deasserted on a byte boundary (multiples of eight bits); otherwise, the operation is aborted

and no data are programmed. The programming of the data bytes is internally self-timed and takes place in a

maximum time of tP (the program time is a multiple of the tBP time depending on the number of bytes being

programmed). During this time, the RDY/BUSY bit in the Status Register indicates that the device is busy.

The device also incorporates an intelligent programming algorithm that can detect when a byte location fails to

program properly. If a programming error arises, it is indicated by the EPE bit in the Status Register.

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