IA88C00
Data Sheet
Microcontroller
As of Production Version -01
D4 - REIE - Receive Error Interrupt Enable - If this bit is set to 1, any receiver error condition will
cause an interrupt request. Possible receive error conditions include parity error, overrun error and
framing error.
D5 - BRKIE - Break Interrupt Enable - If this bit is set to 1, a transition in either direction on the break
signal will cause an interrupt request.
D6 - CCIE - Control Character Interrupt Enable - If this bit is set to 1, an ASCII Control Character
Detect signal in the URC register will cause an interrupt.
D7 - WUIE - Wake-Up Interrupt Enable - If this bit is set to 1, any of the wake-up conditions that set
the Wake-Up Detect bit (WUD) in the URC register will cause an interrupt request.
Figure 32. UART Transmit Interrupt Register, UTI R238 Bank 0
Bit
7
D7
6
D6
5
D5
4
D4
3
D3
2
D2
1
D1
0
D0
Initial Value
Read/Write
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
1
R/O
0
R/W
The timing for the transmit buffer empty interrupt is software programmable. There are two different
interrupt timings selectable with 1 bit.
Option 1: Interrupt is activated at the moment the contents of the TUIO register are transferred to the Tx
FIFO.
Option 2: Interrupt is activated at the moment the last stop bit in the Tx FIFO is sent.
After loading the transmit shift register, UART control generates a buffer empty flag to indicate that
TUIO is ready to be filled with new data.
A new flag will indicate when the transmit shift register is empty.
D0 - If this bit is zero, a high value of D2 in the UIE register will cause an interrupt on Transmit UIO
empty. If this bit is set, a high value of D2 in the UIE register will cause an interrupt on transmit shift
register empty. That is when the last stop bit is transmitted. This bit should be programmed prior to
writing to the UIO register.
D1 - This flag is set when the transmit shift register is empty and is reset when a new value is loaded into
the UIO. This flag will not be set during a send break.
Figure 33. Uart Data Register (UIO), R239 Bank 0
Bit
7
D7
6
D6
5
D5
4
D4
3
D3
2
D2
1
D1
0
D0
Initial Value
Read/Write
X
R/W
X
R/W
X
R/W
X
R/W
X
R/W
X
R/W
X
R/O
X
R/W
Copyright 2005
ENG 21 0 050519-00
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