W78C58 Datasheet, PDF (14/22 Pages) Winbond – 8-BIT MICROCONTROLLER

W78C58
AC CHARACTERISTICS
The AC specifications are a function of the particular process used to manufacture the part, the
ratings of the I/O buffers, the capacitive load, and the internal routing capacitance. Most of the
specifications can be expressed in terms of multiple input clock periods (TCP), and actual parts will
usually experience less than a ±20 nS variation. The numbers below represent the performance
expected from a 0.8 micron CMOS process when using 2 and 4 mA output buffers.
Clock Input Waveform
XTAL1
T_CH
TCL
FOP, TCP
PARAMETER
SYMBOL
MIN.
Operating Speed
Clock Period
Clock High
Clock Low
FOP
0
TCP
25
TCH
10
TCL
10
Notes:
1. The clock may be stopped indefinitely in either state.
2. The TCP specification is used as a reference in other specifications.
3. There are no duty cycle requirements on the XTAL1 input.
TYP.
-
-
-
-
MAX.
40
-
-
-
Program Fetch Cycle
External Program Memory Fetch Cycle (see Figure 6)
PARAMETER
SYMBOL MIN.
Address Valid to ALE Low
TAAS
1TCP -∆
Address Hold After ALE Low
TAAH
1TCP -∆
ALE Low to PSEN Low
TAPL
1TCP -∆
PSEN Low to Data Valid
TPDA
-
Data Hold After PSEN High
TPDH
0
Data Float After PSEN High
TPDZ
0
ALE Pulse Width
TALW 2TCP -∆
PSEN Pulse Width
TPSW 3TCP -∆
TYP.
-
-
1TCP
-
-
-
2TCP
3TCP
MAX.
-
-
1TCP+∆
2TCP
1TCP
1TCP
2TCP +∆
3TCP +∆
UNIT
MHz
nS
nS
nS
UINT
nS
nS
nS
nS
nS
nS
nS
nS
NOTES
1
2
3
3
NOTES
1
2
3
4
4
- 14 -