C868 Datasheet, PDF (13/82 Pages) Infineon Technologies AG – 8-Bit Single-Chip Microcontroller

C868
CPU
The C868 is efficient both as a controller and as an arithmetic processor. It has extensive
facilities for binary and BCD arithmetic and excels in its bit-handling capabilities. Efficient
use of program memory results from an instruction set consisting of 44% one-byte, 41%
two-byte, and 15% three-byte instructions. With a 10.67 MHz external crystal (giving a
40MHz CPU clock), 58% of the instructions execute in 300 ns.
PSW
Program Status Word Register
[Reset value: 00_H]
D7_H
D6_H
D5_H
D4_H
D3_H
D2_H
D1_H
D0_H
CY
AC
F0
RS1
RS0
OV
F1
P
rwh
rwh
rw
rw
rw
rwh
rw
rwh
Field
P
F1
OV
RS0
RS1
F0
AC
CY
Bits Typ Description
0
rwh Parity Flag
Set/cleared by hardware after each instruction to
indicate an odd/even number of "one" bits in the
accumulator, i.e. even parity.
1
rw General Purpose Flag
2
rwh Overflow Flag
Used by arithmetic instructions.
3
rw Register Bank select control bits
4
These bits are used to select one of the four register
banks.
Table 2 :
RS1 RS0 Function
0 0 Bank 0 selected, data address 00H-07H
0 1 Bank 1 selected, data address 08H-0FH
1 0 Bank 2 selected, data address 10H-17H
1 1 Bank 3 selected, data address 18H-1FH
5
rw General Purpose Flag
6
rwh Auxiliary Carry Flag
Used by instructions which execute BCD operations.
7
rwh Carry Flag
Used by arithmetic instructions.
Data Sheet
13
V 1.0, 2003-05