80C851 Datasheet, PDF (16/22 Pages) NXP Semiconductors – CMOS single-chip 8-bit microcontroller with on-chip EEPROM

Philips Semiconductors
CMOS single-chip 8-bit microcontroller
with on-chip EEPROM
Product specification
80C851/83C851
Table 4. External Clock Drive XTAL1
SYMBOL
PARAMETER
t_CLCL
Oscillator clock period
t_HIGH
HIGH time
t_LOW
LOW time
t_r
Rise time
t_f
Fall time
t_CY
Cycle time¹
NOTE:
1. t_CY = 12 t_CLCL.
VARIABLE CLOCK
f = 1.2 – 16MHz
MIN
MAX
63
833
20
t_CLCL – t_LOW
20
t_CLCL – t_HIGH
–
20
–
20
0.75
10
VARIABLE CLOCK
f = 3.5 – 24MHz
MIN
MAX
42
286
17
t_CLCL – t_LOW
17
t_CLCL – t_HIGH
–
5
–
5
0.5
3.43
UNIT
ns
ns
ns
ns
ns
ms
V_DD–0.5
0.45V
0.7V_DD
0.2V_DD–0.1
t_CHCL
t_CLCX
t_CHCX
t_CLCH
t_CLCL
Figure 8. External Clock Drive
2.4V
2.0V
0.45V
0.8V
NOTE:
AC inputs during testing are driven at 2.4V for a logic ‘1’ and 0.45V for a logic ‘0’.
Timing measurements are made at 2.0V min for a logic ‘1’ and 0.8V for a logic ‘0’.
Figure 9. AC Testing Input/Output
V_LOAD+0.1V
V_LOAD
V_LOAD–0.1V
TIMING
REFERENCE
POINTS
V_OH–0.1V
V_OL+0.1V
NOTE:
For timing purposes, a port is no longer floating when a 100mV change from load voltage occurs, and begins to float when a 100mV change
≥ ± from the loaded V_OH/V_OL level occurs. I_OH/I_OL
20mA.
Figure 10. Float Waveform
1998 Jul 03
16