Translation - Japanese: S70FS01GAフラッシュ メモリのステータスレジスタ-1のリード– KBA221813- Community Translated (JA)
How can I read Status Register-1 on the S70FS01GS flash memory if my application doesn’t know the number of latency dummy cycles in advance?
The S70FS01GS flash memory does not support the Read Status Register-1 (RDSR1: 05h) command because it is a dual-die device where every die set of registers must be addressed separately. The Read Any Register (RDAR: 65h) command must be used instead to read device registers. However, this command uses a predefined number of latency dummy cycles as shown in Figure 1:
Figure1. Read Any Register Read Command Sequence
The number of latency dummy cycles is defined in the Configuration Register-2 as shown in Table 1:
Table 1: Configuration Register 2 Non-volatile (CR2NV)
The number of latency dummy cycles for the RDAR command varies based on the used SPI frequency as detailed in Table 2:
Table 2: Latency Code (Cycles) Versus Frequency
Read Command Maximum Frequency (MHz)
Mode Cycles = 0
Additionally, S70FS01GS has two separate set of registers for its two FS512S dies. Each set of registers needs to be accessed and configured separately. Address A26 = 0 selects the lower address FS512S die and A26 = 1 selects the higher address FS512S die.
In other words, to access the registers on the lower FS512S die, use the address range: [0x00000000 … 0x00800040] and for the upper FS512S die registers, use the address range: [0x04000000 … 0x04800040].