DS89C420-QCL Datasheet, PDF (54/139 Pages) Maxim Integrated Products – Ultra-High-Speed Flash Microcontroller User’s Guide

Ultra-High-Speed Flash
Microcontroller User’s Guide
Table 5-1 shows each instruction, the number of clocks used in the ultra-high-speed microcontroller, and the number used in the 8051 for
comparison. The factor by which the ultra-high-speed microcontroller improves on the 8051 is shown as the speed advantage. A speed
advantage of 12 means that the ultra-high-speed microcontroller performs the same instruction 12 times faster than the original 8051.
Table 5-2 provides a summary by instruction type. Note that many of the instructions provide multiple op codes. As an example, the
ADD A, Rn instruction can act on one of eight working registers. There are eight op codes for this instruction because it can be used
on eight independent locations. Table 5-2 shows totals for both number of instructions and number of op codes. Averages are provid-
ed in the tables. However, the real speed improvement seen in any system depends on the instruction mix.
Table 5-1. INSTRUCTION TIMING COMPARISON
Ultra-high-speed microcontroller is abbreviated as UHSM.
UHSM
UHSM
HEX CLOCK
TIME
INSTRUCTION
CODE CYCLES
@ 25MHz
ADD A, Rn
28..2F
1
40 ns
ADD A, direct
25
2
80 ns
ADD A, @Ri
26..27
2
80 ns
ADD A, #data
24
2
80 ns
ADDC A, Rn
38..3F
1
40 ns
ADDC A, direct
ADDC A, @Ri
ADDC A, #data
35
2
36..37
2
34
2
80 ns
80 ns
80 ns
SUBB A, Rn
98..9F
1
40 ns
SUBB A, direct
95
2
80 ns
SUBB A, @Ri
96..97
2
80 ns
SUBB A, #data
94
2
80 ns
INC A
04
1
40 ns
INC Rn
08..0F
1
40 ns
INC direct
INC @Ri
05
2
06..07
2
80 ns
80 ns
INC DPTR
A3
1
40 ns
DEC A
14
1
40 ns
DEC Rn
18..1F
1
40 ns
DEC direct
15
2
80 ns
DEC @Ri
16..17
2
80 ns
MUL AB
A4
9
360 ns
DIV AB
84
10
400 ns
DA A
ANL A, Rn
D4
2
58..5F
1
80 ns
40 ns
ANL A, direct
55
2
80 ns
ANL A, @Ri
56..57
2
80 ns
ANL A, #data
54
2
80 ns
ANL direct, A
52
2
80 ns
ANL direct, #data
53
3
120 ns
8051
CLOCK
CYCLES
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
12
24
12
12
12
12
48
48
12
12
12
12
12
12
24
8051
TIME
@ 25MHz
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
960 ns
480 ns
480 ns
480 ns
480 ns
960 ns
960 ns
480 ns
480 ns
480 ns
480 ns
480 ns
480 ns
960 ns
UHSM vs.
8051 SPEED
ADVANTAGE
12
6
6
6
12
6
6
6
12
6
6
6
12
12
6
6
24
12
12
6
6
5.33
4.80
6
12
6
6
6
6
8
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