AT45DB641E datasheet(8/69 Pages) RENESAS

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AT45DB641E

DS-45DB641E-027N–DFLASH–2/2022

A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum

SCK frequency allowable for the Continuous Array Read is defined by the f

CAR4 specification. The Continuous Array

Read bypasses both data buffers and leaves the contents of the buffers unchanged.

5.3

Continuous Array Read (High Frequency Mode: 0Bh Opcode)

This command can be used to read the main memory array sequentially at higher clock frequencies up to the maximum

specified by f

CAR1. To perform a Continuous Array Read using the standard DataFlash page size (264 bytes), the CS pin

must first be asserted, and then an opcode of 0Bh must be clocked into the device followed by three address bytes and

one dummy byte. The first 15 bits (PA14 - PA0) of the 24-bit address sequence specify which page of the main memory

array to read and the last 9 bits (BA8 - BA0) of the 24-bit address sequence specify the starting byte address within the

page. To perform a Continuous Array Read using the binary page size (256 bytes), the opcode 0Bh must be clocked into

the device followed by three address bytes (A22 - A0) and one dummy byte. Following the dummy byte, additional clock

pulses on the SCK pin will result in data being output on the SO pin.

The CS pin must remain low during the loading of the opcode, the address bytes, the dummy byte, and the reading of

data. When the end of a page in the main memory is reached during a Continuous Array Read, the device will continue

reading at the beginning of the next page with no delays incurred during the page boundary crossover (the crossover

from the end of one page to the beginning of the next page). When the last bit in the main memory array has been read,

the device will continue reading back at the beginning of the first page of memory. As with crossing over page

boundaries, no delays will be incurred when wrapping around from the end of the array to the beginning of the array.

A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum

SCK frequency allowable for the Continuous Array Read is defined by the f

CAR1 specification. The Continuous Array

Read bypasses both data buffers and leaves the contents of the buffers unchanged.

5.4

Continuous Array Read (Low Frequency Mode: 03h Opcode)

This command can be used to read the main memory array sequentially at lower clock frequencies up to maximum

specified by f

CAR2. Unlike the previously described read commands, this Continuous Array Read command for the lower

clock frequencies does not require the clocking in of dummy bytes after the address byte sequence. To perform a

Continuous Array Read using the standard DataFlash page size (264 bytes), the CS pin must first be asserted, and then

an opcode of 03h must be clocked into the device followed by three address bytes. The first 15 bits (PA14 - PA0) of the

24-bit address sequence specify which page of the main memory array to read and the last 9 bits (BA8 - BA0) of the

address sequence specify the starting byte address within the page. To perform a Continuous Array Read using the

binary page size (256 bytes), the opcode 03h must be clocked into the device followed by three address bytes (A22 -

A0). Following the address bytes, additional clock pulses on the SCK pin will result in data being output on the SO pin.

The CS pin must remain low during the loading of the opcode, the address bytes, and the reading of data. When the end

of a page in the main memory is reached during a Continuous Array Read, the device will continue reading at the

beginning of the next page with no delays incurred during the page boundary crossover (the crossover from the end of

one page to the beginning of the next page). When the last bit in the main memory array has been read, the device will

continue reading back at the beginning of the first page of memory. As with crossing over page boundaries, no delays will

be incurred when wrapping around from the end of the array to the beginning of the array.

A low-to-high transition on the CS pin will terminate the read operation and tri-state the output pin (SO). The maximum

SCK frequency allowable for the Continuous Array Read is defined by the f

CAR2 specification. The Continuous Array

Read bypasses both data buffers and leaves the contents of the buffers unchanged.

5.5

Continuous Array Read (Low Power Mode: 01h Opcode)

This command is ideal for applications that want to minimize power consumption and do not need to read the memory

array at high frequencies. Like the 03h opcode, this Continuous Array Read command allows reading the main memory

array sequentially without the need for dummy bytes to be clocked in after the address byte sequence. The memory can

be read at clock frequencies up to maximum specified by f

CAR3. To perform a Continuous Array Read using the standard

DataFlash page size (264 bytes), the CS pin must first be asserted, and then an opcode of 01h must be clocked into the

device followed by three address bytes. The first 15 bits (PA14 - PA0) of the 24-bit address sequence specify which page

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