DS89C420 Dallas Semiconducotr, DS89C420 Datasheet - Page 49

• Manufacturer Part Number: DS89C420
• Description: Ultra-High-Speed Microcontroller
• Manufacturer: Dallas Semiconducotr

Note 1: The system clock frequency is dependent on the oscillator frequency and the setting of the clock-divide control bits (CD1 and CD0) and the crystal
Note 2: External MOVX instruction times are dependent on the setting of the MD2, MD1, and MD0 bits in the clock control register. The terms
Note 3: Maximum load capacitance (to meet the above timing) for Port 0, ALE,
MD2
multiplier control bits (4X/
of the table given below.
“t
(except for P3.6,
the frequency of the selected crystal.
0
0
0
0
1
1
1
1
STC1
4X/
, t
X
X
X
1
0
2
STC2
X
MD1
1
0
0
1
1
1
0
0
, t
STC3
” used in the variable timing table are calculated through the use of the table given below.
MD0
CD1
1
0
1
0
1
WR
0
1
0
0
0
0
1
1
and P3.7,
MOVX INSTRUCTION TIME
2
X
(MACHINE CYCLES)
and CTM) in the PMR register. The term “1 / t
CD0
0
0
1
0
1
RD
10
11
12
) are tested with a capacitance of 50pF. XTAL1 and XTAL2 load capacitance is dependent on
2
3
4
5
9
4 Oscillator Cycles
2 Oscillator Cycles
Reserved
1 Oscillator Cycle
1 / 1024 Oscillator Cycle
NUMBER OF OSCILLATOR CYCLES
PER SYSTEM CLOCK (1 / t
49 of 59
(t
t
CLCL
STC1
10
14
18
22
26
0
2
6
)
PSEN
CLCL
(t
t
STC2
CLCL
” used in the variable timing table is calculated through the use
0
1
1
1
5
5
5
5
,
CLCL
)
WR
)
, and
(t
t
CLCL
STC3
0
0
0
0
4
4
4
4
)
RD
is limited to 60pF. Port 1, 2, 3, and 4
(t
t
CLCL
STC4
0
0
0
0
1
1
1
1
)
(t
t
CLCL
STC5
0
1
1
1
1
1
1
1
)