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Renesas Electronics America - Knowledgebase

Where to verify the serial flash memory for the timing as boot memory?

Latest Updated:12/22/2010


I would like to verify the serial flash memory that will be used satisfies the timing as the boot memory. Which document should I refer to?


Serial flash boot (boot modes 1 and 3) is described in the application note "High-speed Read/Write Serial Flash Memory Using
the Renesas Serial Peripheral lnterface" (Document number: REJ06B0889-0100).
Serial flash boot reads the program data from the serial flash memory which is connected to the MCU.
Note that the serial flash memory must satisfy the timing described in Tables 4 and 5 on application note page 10.

Internal ROM program to boot which is included in the CPU sets RSPI channel 0 as follows:

(1) Bit rate register (SPBR)
Boot mode 1 (BΦ/2): 0x00 (division ratio: 2)
Boot mode 3 (BΦ/4): 0x01 (division ratio: 4)

(2) Command register (SPCMD)
SCKDEN bit = b'0 (RSPCK delay is 1 RSPCK)
SLNDEN bit = b'0 (SSL negation delay is 1 RSPCK)
SPNDEN bit = b'0 (0: Next access delay is 1 RSPCK + 2 BΦ)
BRDV [1:0] bits = b'00 (specify the base bit rate)

Suitable Products
SH7266, SH7267
SH7262, SH7264