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UART
MOTOROLA
MC68328 DRAGONBALL PROCESSOR USER’S MANUAL
8-9
UNUSED
These bits are unused and read 0.
PRESCALER
These bits control the divide value of the baud generator prescaler. The divide value is
determined by the following formula:
prescaler divide value = 65 (decimal) - PRESCALER
8.2.7 Receiver Register
This register controls the receiver. Status of each received character is also read from this
register. The high byte of this register resets to $00. The low byte contains random data until
the first character is received.
FIFO FULL
This read-only bit indicates that the receiver FIFO is full and may generate an overrun.
0 = Receive FIFO not full (no interrupt posted)
1 = Receive FIFO full (interrupt posted)
FIFO HALF
This read-only bit indicates that the receiver FIFO is more than half full.
0 = Receive FIFO less than half full (no interrupt posted)
1= Receive FIFO more than half full (interrupt posted)
DATA READY
This read-only bit indicates that at least one byte is present in the receive FIFO.
0 = No data in receive FIFO
1 = Data in receive FIFO
OVRUN
FIFO Overrun
While high, this read-only bit indicates that the receiver overwrote data in the FIFO. The
character with this bit set is valid but at least one previous character was lost. Under nor-
mal circumstances, this bit should never be set. It indicates that the user’s software is not
keeping up with the incoming data rate. This bit is updated and valid for each received
character.
0 = No FIFO overrun
1 = FIFO overrun detected
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
FIFO
FULL
FIFO
HALF
DATA
READY
0
OVRUN
FRAME
ERROR
BREAK
PARITY
ERROR
RX DATA
ADDRESS: $(FF)FFF904
Reset Value: $0000
Figure 8-4. Receiver Register
Содержание DragonBall MC68328
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Страница 25: ...Overview 1 14 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Страница 45: ...System Integration Module 2 20 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Страница 103: ...Parallel Ports 7 16 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Страница 117: ...UART 8 14 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Страница 127: ...SPI Master 10 6 MC68328 DRAGONBALL PROCESSOR USER S MANUAL MOTOROLA ...
Страница 137: ...Electrical Characteristics PRELIMINARY MOTOROLA MC68328 DRAGONBALL PROCESSOR USER S MANUAL 13 4 ...