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SPI-Slave
9-2
MC68328 DRAGONBALL PROCESSOR USER’S MANUAL
MOTOROLA
If enabled, the SPIS operates even if the system clock is inactive. After the SPIS receives a
data byte from an external master, the SPIS interrupt is posted. If the system is in sleep
mode, this interrupt can initiate the wakeup sequence for restoring the system clock. The
SPIS bit (bit 21) in the wakeup control register IWR (at location 0x(FF)FFF308) must be set
for the wakeup sequence to occur.
9.3 SIGNAL DESCRIPTIONS
SPSRXD
This pin is the serial data input to the shift register. A new bit is shifted in on each leading
edge of SPSCLK while in normal mode(POL=0) or on each trailing edge of SPSCLK in
polarity-inverted mode(POL=1). This signal pin is multiplexed with other signals to port K,
bit 4. Refer to Section 7.1.10
for more details.
SPSCLK
This pin is the shift clock input.
SPSEN
This pin indicates that an SPI transfer is in progress. After the enable becomes active, the
SPIS state machine responds to clock edges for data transfer.
9.4 SPIS REGISTER
This register controls the SPIS operation and reports its status. The data register contains
the data transmitted by the external master. After reset, all bits are set to $0000.
Figure 9-2. SPIS Operation
SPSCLK
SPSRXD
B7
B6
B5
B4
B3
B2
B1
B0
SPSCLK
SPSCLK
SPSCLK
(POL=1, PHA=1)
(POL=1, PHA=0)
(POL=0, PHA=1)
(POL=0, PHA=0)
SPSEN
Summary of Contents for DragonBall MC68328
Page 5: ...vi MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Page 25: ...Overview 1 14 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Page 45: ...System Integration Module 2 20 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Page 103: ...Parallel Ports 7 16 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Page 117: ...UART 8 14 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Page 127: ...SPI Master 10 6 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...