W55P241 Datasheet, PDF (8/32 Pages) List of Unclassifed Manufacturers – I/O device usable with many different microprocessors through SPI interface

W55P241
/CS
Write command
CLK
DI “1”C6 C5 C4 C3 C2 C1 C0 W7 W6 W5 W4 W3 W2 W1 W0
DO
HZ
/CS
Read command
CLK
DI “0”C6 C5 C4 C3 C2 C1 C0 X X X X X X X X
DO
HZ
R7 R6 R5 R4 R3 R2 R1 R0
Cn: command bit. Wn: write data bit. Rn: read data bit.
HZ: high impedance. X : don’t care.7 -> 0: MSB -> LSB.
Figure 4 Write command and read command
The command byte’s Bit7 determines “write data to W55P241” or “read data from W55P241”. The
command byte’s Bit6 selects slave device 0 or slave device 1. Bit5 and bit4 of command byte specify
the command group while Bit3~bit0 of command byte control some Special Function Registers (SFR)
in one specific group. The following table roughly lists all the commands.
Command
Write
Read
Reset
No response
Read/write
Bit7
1
0
Device
Group
Special Function Register
Bit6
Bit5 Bit4 Bit3 Bit2 Bit1 Bit0
0 or 1
SFR of one specific group
0 or 1
SFR of one specific group
0xFF
Settings except write, read and reset commands
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