W78C438C Datasheet, PDF (9/16 Pages) Winbond – 8-BIT MICROCONTROLLER

W78C438C
BIT ADDR.
7 0C7H
6 0C6H
5 0C5H
4 0C4H
3 0C3H
2 0C2H
1 0C1H
0 0C0H
NAME
PX3
EX3
IE3
IT3
PX2
EX2
IE2
IT2
FUNCTION
High/low priority level for INT3 is specified when this bit is set/cleared by software.
Enable/disable interrupt from INT3 when this bit is set/cleared by software.
If IT3 is "1," IE3 is set/cleared automatically by hardware when interrupt is
detected/serviced.
INT3 is falling-edge/low-level triggered when this bit is set/cleared by software.
High/low priority level for INT2 is specified when this bit is set/cleared by software.
Enable/disable interrupt from INT2 when this bit is set/cleared by software.
If IT2 is "1," IE2 is set/cleared automatically by hardware when interrupt is
detected/serviced.
INT2 is falling-edge/low-level triggered when this bit is set/cleared by software.
Table 2. Functions of XICON Register
INTERRUPT SOURCE
External Interrupt 0
Timer/Counter 0
External Interrupt 1
Timer/Counter 1
Serial Port
Timer/Counter 2
External Interrupt 2
External Interrupt 3
VECTOR ADDRESS
03H
0BH
13H
1BH
23H
2BH
33H
3BH
Table 3. Priority of Interrupts
PRIORITY SEQUENCE
0 (Highest)
1
2
3
4
5
6
7 (Lowest)
Newly Added Special Function Registers
The W78C438C uses four newly defined special function registers, which are described in Table 4. To
read/write these registers, use the "MOV direct" or "read-modify-write" instructions.
REGISTER ADDR.
FUNCTION
LENGTH R/W VALUE
TYPE ^AFTER
RESET
1
HB
A1H During the execution of "MOVX @Ri," the content of HB is output to
8
R/W 00H
AP6.
2
EPMA
A2H EPMA.7 determines functions of AP7.
8
R/W 70H
EPMA.3−EPMA.0 determine values of AP7<3:0> when EPMA.7 is
"0."
3
P8
A6H The content of P8 is output to port 8.
8
R/W 0FFH
4
XICON
C0H _{The bits of XICON determine/show the functions/status of INT2 −}
8
R/W 00H
INT3 . Bit-addressable.
Table 4. Newly Added Special Function Registers of the W78C438C
Publication Release Date: July 1998
-9-
Revision A1