USB84604 datasheet(33/61 Pages) MICROCHIP

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 2014-2016 Microchip Technology Inc.

DS60001295C-page 33

USB84604

7.1.5

ERASE EXAMPLE

To perform a SCTR_ERASE, 32BLK_ERASE, or 64BLK_ERASE, the device writes 0x20, 0x52, or 0xD8, respectively

to the first byte of the command buffer, followed by a 3-byte address. The length of the transfer is set to 4 bytes. To

perform this, the device drives SPI_CE_N low, then counts out 8 clocks. It then outputs on SPI_DO the 8 bits of com-

mand, followed by 24 bits of address of the location to be erased. When the transfer is complete, SPI_CE_N goes high,

while the SPI_DI line is ignored in this example.

7.1.6

BYTE PROGRAM EXAMPLE

To perform a Byte Program, the device writes 0x02 to the first byte of the command buffer, followed by a 3-byte address

of the location that will be written to, and one data byte. The length of the transfer is set to 5 bytes. The device first drives

SPI_CE_N low, then SPI_DO outputs 8 bits of command, followed by 24 bits of address, and one byte of data. SPI_DI

is not used in this example.

7.1.7

COMMAND ONLY PROGRAM EXAMPLE

To perform a single byte command such as the following:

•WRDI

•WREN

•EWSR

• CHIP_ERASE

• EBSY

• DBSY

The device writes the opcode into the first byte of the SPI_CMD_BUF and the SPI_CMD_LEN is set to one. The device

first drives SPI_CE_N low, then 8 bits of the command are clocked out on SPI_DO. SPI_DI is not used in this example.

FIGURE 7-3:

SPI ERASE SEQUENCE

SPI_CE_N

SPI_CLK

23 24

12 3 4

ADD.

SPI_DO

SPI_DI

Command

MSB

ADD.

HIGH IMPEDANCE

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