W77E532 Datasheet, PDF (32/86 Pages) Winbond – 8 BIT MICROCONTROLLER

W77E532/W77E532A
7. INSTRUCTION
The W77E532A executes all the instructions of the standard 8032 family. The operation of these
instructions, their effect on the flag bits and the status bits is exactly the same. However, timing of
these instructions is different. The reason for this is two fold. Firstly, in the W77E532A, each machine
cycle consists of 4 clock periods, while in the standard 8032 it consists of 12 clock periods. Also, in the
W77E532A there is only one fetch per machine cycle i.e. 4 clocks per fetch, while in the standard 8032
there can be two fetches per machine cycle, which works out to 6 clocks per fetch.
The advantage the W77E532A has is that since there is only one fetch per machine cycle, the number
of machine cycles in most cases is equal to the number of operands that the instruction has. In case of
jumps and calls there will be an additional cycle that will be needed to calculate the new address. But
overall the W77E532A reduces the number of dummy fetches and wasted cycles, thereby improving
efficiency as compared to the standard 8032.
Table 2. Instructions that affect Flag settings
INSTRUCTION
ADD
CARRY
X
OVERFLOW
AUXILIARY
CARRY
INSTRUCTION
X
X
CLR C
CARRY
0
OVERFLOW
AUXILIARY
CARRY
ADDC
SUBB
X
X
X
X
X
CPL C
X
X
ANL C, bit
X
MUL
0
X
ANL C, bit
X
DIV
DA A
0
X
X
ORL C, bit
X
ORL C, bit
X
RRC A
X
MOV C, bit
X
RLC A
X
CJNE
X
SETB C
1
A “X” indicates that the modification is as per the result of instruction.
- 32 -
Publication Release Date: June 30, 2009
Revision A10