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SPI-Master
MOTOROLA
MC68328 DRAGONBALL PROCESSOR USER’S MANUAL
10-3
SPMTxD
Transmit Data
This pin is the shift-register output. A new data bit is presented on each rising edge of the
SPMCLK in normal mode or on each falling edge of SPMCLK in inverted mode.
SPMRxD
Receive Data
This pin is the shift-register input. A new bit is shifted in on each falling edge of SPMCLK
while in normal mode or on each rising edge of SPMCLK in inverted mode.
SPMCLK
Shift Clock
This pin is the clock output. When the SPIM is enabled, a selectable number of clock puls-
es is issued. While POL = 0, this signal is low while the SPIM is idle. When POL = 1, this
signal is high during idle.
10.4 SPIM REGISTERS
These registers control the SPIM operation and report its status. The data register
exchanges data with external slave devices. After reset, all bits are set to $0000.
10.4.1 SPIM Control/Status Register
This register controls the SPIM operation and reports its status.
DATA RATE
These bits select the baud rate of the SPMCLK based of divisions of the system clock.
The master clock for the SPIM is SYSCLK. The bits are encoded as:
000 = Divide by 4
001 = Divide by 8
010 = Divide by 16
011 = Divide by 32
100 = Divide by 64
101 = Divide by 128
110 = Divide by 256
111 = Divide by 512
SPMEN
This bit enables the SPIM. The enable should be asserted before initiating an exchange
and should be negated after the exchange is complete.
0 = SPI master disable
1 = SPI master enable
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DATA RATE
RESVD
RESVD
RESVD SPMEN
XCH
SPMIRQ IRQEN
PHA
POL
BIT COUNT
Address: (FF)FFF802
Reset Value: $0000
Figure 10-3. SPIM Control/Status Register
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 ...