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SPI-Master
MOTOROLA
MC68328 DRAGONBALL PROCESSOR USER’S MANUAL
10-5
10.4.2 SPIM Data Register
This register exchanges data with external slave devices.
DATA
These are the data bits to be exchanged with the external device. The data must be load-
ed before the XCH bit is set. At the end of the exchange, data from the peripheral is
present in this register. These bits contain unknown data if they are read while the XCH
bit is set. A write to these bits will be ignored while the XCH bit is set. As data is shifted
MSB first, outgoing data is automatically MSB-justified. For example, if the exchange
length is 10 bits, the MSB of the outgoing data is bit 9. The first bit presented to the exter-
nal slave device will be bit 9, followed by the remaining 9 bits.
NOTE
Users should reload the data every time for each transfer before
setting the XCH bit or the enable bit.
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
DATA
Address: (FF)FFF800
Reset Value: $0000
Figure 10-4. SPIM Data 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 ...