
W78E58B
- 8 -
XICON - external interrupt control (C0H)
PX3
EX3
IE3
IT3
PX2
EX2
IE2
IT2
PX3: External interrupt 3 priority high if set
EX3: External interrupt 3 enable if set
IE3: If IT3 = 1, IE3 is set/cleared automatically by hardware when interrupt is detected/serviced
IT3: External interrupt 3 is falling-edge/low-level triggered when this bit is set/cleared by software
PX2: External interrupt 2 priority high if set
EX2: External interrupt 2 enable if set
IE2: If IT2 = 1, IE2 is set/cleared automatically by hardware when interrupt is detected/serviced
IT2: External interrupt 2 is falling-edge/low-level triggered when this bit is set/cleared by software
Eight-source interrupt information
INTERRUPT
SOURCE
VECTOR
ADDRESS
POLLING
SEQUENCE WITHIN
PRIORITY LEVEL
ENABLE
REQUIRED
SETTINGS
INTERRUPT
TYPE
EDGE/LEVEL
External Interrupt 0
03H
0 (highest)
IE.0
TCON.0
Timer/Counter 0
0BH
1
IE.1
-
External Interrupt 1
13H
2
IE.2
TCON.2
Timer/Counter 1
1BH
3
IE.3
-
Serial Port
23H
4
IE.4
-
Timer/Counter 2
2BH
5
IE.5
-
External Interrupt 2
33H
6
XICON.2
XICON.0
External Interrupt 3
3BH
7 (lowest)
XICON.6
XICON.3
P4CONB (C3H)
BIT
NAME
FUNCTION
7, 6
P43FUN1
P43FUN0
00: Mode 0. P4.3 is a general purpose I/O port which is the same as Port1.
01: Mode 1. P4.3 is a Read Strobe signal for chip select purpose. The address
range depends on the SFR P43AH, P43AL, P43CMP1 and P43CMP0.
10: Mode 2. P4.3 is a Write Strobe signal for chip select purpose. The address
range depends on the SFR P43AH, P43AL, P43CMP1 and P43CMP0.
11: Mode 3. P4.3 is a Read/Write Strobe signal for chip select purpose. The
address range depends on the SFR P43AH, P43AL, P43CMP1, and
P43CMP0.