D a t a S h e e t ( P r e l i m i n a r y )
6. Spansion SPI Modes
A microcontroller can use either of its two SPI modes to control Spansion SPI Flash memory devices:
CPOL = 0, CPHA = 0 (Mode 0)
CPOL = 1, CPHA = 1 (Mode 3)
Input data is latched in on the rising edge of SCK, and output data is available from the falling edge of SCK for
both modes.
When the bus master is in standby mode, SCK is as shown in Figure 6.2 for each of the two modes:
SCK remains at 0 for (CPOL = 0, CPHA = 0 Mode 0)
SCK remains at 1 for (CPOL = 1, CPHA = 1 Mode 3)
Figure 6.1 Bus Master and Memory Devices on the SPI Bus
SO
SPI Interface with
(CPOL, CPHA) =
(0, 0) or (1, 1)
SI
SCK
SCK SO SI
SCK SO SI
SCK SO SI
Bus Master
SPI Memory
SPI Memory
SPI Memory
Device
Device
Device
CS3 CS2 CS1
CS#
W# HOLD#
CS#
W# HOLD#
CS#
W# HOLD#
Note
The Write Protect (W#) and Hold (HOLD#) signals should be driven high (logic level 1) or low (logic level 0) as appropriate.
Figure 6.2 SPI Modes Supported
CS#
CPOL CPHA
Mode 0
SCK
0
0
1
1
Mode 3
SCK
SI
MSB
SO
MSB
August 31, 2006 S25FL040A_00_B0
S25FL040A
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SPANSION [ SPANSION ]
