XR68C681 Datasheet, PDF (64/75 Pages) Exar Corporation – CMOS Dual Channel UART (DUART)

XR68C681
Bit 7
Input Port
Change
 J 8
 J E%
Bit 6
Delta Break
B
 J 8
 J E%
Bit 5
RXRDY/
FFULLB
 J 8
 J E%
Bit 4
TXRDYB
 J 8
 J E%
Bit 3
Counter #1
Ready
 J 8
 J E%
Bit 2
Delta Break
A
 J 8
 J E%
Bit 1
RXRDY/
FFULLA
 J 8
 J E%
Table 28. Interrupt Status Register, ISR
Bit 7
Input Port
Change
 J ++
 J 
Bit 6
Delta Break
B
 J ++
 J 
Bit 5
RXRDY/
FFULLB
 J ++
 J 
Bit 4
TXRDYB
 J ++
 J 
Bit 3
Counter #1
Ready
 J ++
 J 
Bit 2
Delta Break
A
 J ++
 J 
Bit 1
RXRDY/
FFULLA
 J ++
 J 
Table 29. Interrupt Mask Register, IMR
Bit 7

.6
Bit 6

.=
Bit 5

.1
Bit 4

.
Bit 3

.
Bit 2

.
Table 30. Counter/Timer Upper Byte Register, CTUR
Bit 1

.
Bit 7

.@
Bit 6

./
Bit 5

.6
Bit 4

.=
Bit 3

.1
Bit 2

.
Table 31. Counter/Timer Lower Byte Register, CTLR
Bit 1

.
Bit 7
#;@
Bit 6
#;/
Bit 5
#;6
Bit 4
#;=
Bit 3
#;1
Bit 2
#;
Table 32. Interrupt Vector Register: IVR
Bit 1
#;
Bit 0
TXRDYA
 J 8
 J E%
Bit 0
TXRDYA
 J ++
 J 
Bit 0

.<
Bit 0

.
Bit 0
#;
 
/=