Generic Serial Flash Interface Intel® FPGA IP User Guide

ID 683419
Date 11/09/2021
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1.8.3. Flash Operations to Write Flash Registers

The following flash operations are used to write flash registers:

  • Write enhanced volatile configuration register
  • Write bank register
  • Write status register
  • Write configuration register
Note: You must execute the write enable operation before you start these operations.

The following registers are used to write the status of a register:

  • Flash command setting register
  • Flash command control register
  • Flash command write data 0 register

Perform the Write Status Register Operation to Protect Sector of Flash

proc write_status_register { } {
 global mp flash_cmd_setting flash_cmd_write_data_0 flash_cmd_ctrl
master_write_32 $mp $flash_cmd_setting 0x00001001
master_write_32 $mp $flash_cmd_write_data_0 0x0000007c
master_write_32 $mp $flash_cmd_ctrl 0x1
}

To perform the write status register operation, follow these steps:

  1. Define the global variables.
  2. Customize the write status register operation by writing to the flash command setting register.
    1. Set bit [7:0] of this register to 01 as 01h is the operation code of the write status register operation.
    2. Set bit [10:8] to 0 as this operation does not carry any address byte.
    3. Set bit 11 to 0 as the number of byte declared in bit [15:12] is the write data to the flash device.
    4. Set bit [15:12] to 1 as you will be writing 1 byte (8 bits) of data into the status register.
  3. Write the data to set the sector protection into the flash command write data 0 register.
    1. Bit 6 and bit [4:2] of the status register are the block protect bits and bit 5 is the Top/Bottom bit. In this example, protection is required for all sectors from the bottom of the memory array. For more information, refer to the respective flash datasheet.
  4. Write 1 to bit 0 of the flash command control register to start the write status register for the sector protect operation.