XR16V798_08 Datasheet, PDF (23/56 Pages) Exar Corporation – HIGH PERFORMANCE 2.25V TO 3.6V OCTAL UART WITH FRACTIONAL

REV. 1.0.1
3.1.1.1
XR16V798
HIGH PERFORMANCE 2.25V TO 3.6V OCTAL UART WITH FRACTIONAL BAUD RATE
INT0 Channel Interrupt Indicator:
INT0 Register
Individual UART Channel Interrupt Status
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
Ch-7 Ch-6 Ch-5 Ch-4 Ch-3 Ch-2 Ch-1 Ch-0
3.1.1.2 INT1, INT2 and INT3 Interrupt Source Locator
INT3, INT2 and INT1 provide a 24-bit (3 bits per channel) encoded interrupt indicator. Table 9 shows the 3 bit
encoding and their priority order. The 16-bit Timer time-out interrupt will show up only as a channel 0 interrupt.
For other channels, interrupt 7 is reserved.
.
FIGURE 13. THE GLOBAL INTERRUPT REGISTERS, INT0, INT1, INT2 AND INT3
Interrupt Registers,
INT0, INT1, INT2 and INT3
INT3 Register
INT2 Register
INT1 Register
Channel-7
Bit Bit Bit
21 0
Channel-6
Bit Bit Bit
21 0
Channel-5
Bit Bit Bit
21 0
Channel-4
Bit Bit Bit
21 0
Channel-3
Bit Bit Bit
21 0
Channel-2
Bit Bit Bit
21 0
Channel-1
Bit Bit Bit
21 0
Channel-0
Bit Bit Bit
21 0
INT0 Register
Ch-7 Ch-6 Ch-5 Ch-4 Ch-3 Ch-2 Ch-1 Ch-0
Bit-7 Bit-6 Bit-5 Bit-4 Bit-3 Bit-2 Bit-1 Bit-0
TABLE 9: UART CHANNEL [7:0] INTERRUPT SOURCE ENCODING AND CLEARING
PRIORITY
Bit
2
Bit
1
Bit
0
INTERRUPT SOURCE(S) AND CLEARING
x
0 0 0 None or wake-up indicator
1
0 0 1 RXRDY & RX Line Status (logic OR of LSR[4:1]). RXRDY INT clears by reading data in the RX
FIFO until it falls below the trigger level; RX Line Status INT cleared after reading LSR register.
2
0 1 0 RXRDY Time-out: Cleared same way as RXRDY INT.
3
0 1 1 TXRDY, THR or TSR (auto RS485 mode) empty, clears after reading ISR register.
4
1 0 0 MSR, RTS/CTS or DTR/DSR delta or Xoff/Xon or special character detected. The first two
clears after reading MSR register; Xoff/Xon or special char. detect INT clears after reading ISR
register.
5
1 0 1 Reserved.
6
1 1 0 Reserved.
7
1 1 1 TIMER Time-out, shows up as a channel 0 INT. It clears after reading the TIMERCNTL register.
Reserved in other channels.
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