CHAPTER 19 SERIAL INTERFACE UNIT 1 (SIU1)
User’s Manual U14272EJ3V0UM
367
Table 19-3. Interrupt Function
SIUIID_1 register
Interrupt set/reset function
Bit 3
Note
Bit 2
Bit 1
Priority level
Interrupt type
Interrupt source
Interrupt reset control
0
1
1
Highest (1st) Receive line
status
Overrun error, parity error, framing error,
or break interrupt
Read line status register
0
1
0
2nd
Receive data
ready
Receive data exists or has reached the
trigger level.
Read the receive buffer
register or lower the
data in the FIFO than
trigger level.
1
1
0
2nd
Character
timeout
During the time period for the four most
recent characters, not one character has
been read from the receive FIFO nor has
a character been input to the receive
FIFO. During this period, at least one
character has been held in the receive
FIFO.
Read receive buffer
register
0
0
1
3rd
Transmit
holding
register
empty
Transmit register is empty
Read IIR (if it is the
interrupt source) or write
to transmit holding
register
0
0
0
4th
Modem
status
CTS1#, DSR1#, or DCD1#
Read modem status
register
Note FIFO mode only.
Содержание VR4181 mPD30181
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