Instruction set – Rainbow Electronics W79E8213R User Manual
Page 41
Preliminary W79E8213/W79E8213R Data Sheet
Publication Release Date: July 11, 2008
- 41 -
Revision A2
9. INSTRUCTION
SET
The W79E8213 series execute all the instructions of the standard 8052 family. The operations of
these instructions, as well as their effects on flag and status bits, are exactly the same. However, the
timing of these instructions is different in two ways. Firstly, the machine cycle is four clock periods,
while the standard-8051/52 machine cycle is twelve clock periods. Secondly, it can fetch only once per
machine cycle (i.e., four clocks per fetch), while the standard 8051/52 can fetch twice per machine
cycle (i.e., six clocks per fetch).
The timing differences create an advantage for the W79E8213 series. There is only one fetch per
machine cycle, so the number of machine cycles is usually equal to the number of operands in the
instruction. (Jumps and calls do require an additional cycle to calculate the new address.) As a result,
the W79E8213 series reduces the number of dummy fetches and wasted cycles, and therefore
improves overall efficiency, compared to the standard 8051/52.
Op-code HEX
Code
Bytes
W79E8213
series
Machine
Cycle
W79E8213
series
Clock
cycles
8032
Clock
cycles
W79E8213
series vs. 8032
Speed Ratio
NOP
00 1
1 4 12
3
ADD A, R0
28
1
1
4
12
3
ADD A, R1
29
1
1
4
12
3
ADD A, R2
2A
1
1
4
12
3
ADD A, R3
2B
1
1
4
12
3
ADD A, R4
2C
1
1
4
12
3
ADD A, R5
2D
1
1
4
12
3
ADD A, R6
2E
1
1
4
12
3
ADD A, R7
2F
1
1
4
12
3
ADD A, @R0
26
1
1
4
12
3
ADD A, @R1
27
1
1
4
12
3
ADD A, direct
25
2
2
8
12
1.5
ADD A, #data
24
2
2
8
12
1.5
ADDC A, R0
38
1
1
4
12
3
ADDC A, R1
39
1
1
4
12
3
ADDC A, R2
3A
1
1
4
12
3
ADDC A, R3
3B
1
1
4
12
3
ADDC A, R4
3C
1
1
4
12
3
ADDC A, R5
3D
1
1
4
12
3
ADDC A, R6
3E
1
1
4
12
3
ADDC A, R7
3F
1
1
4
12
3
ADDC A, @R0
36
1
1
4
12
3
ADDC A, @R1
37
1
1
4
12
3
ADDC A, direct
35
2
2
8
12
1.5