P8XCE560 Datasheet, PDF (69/84 Pages) NXP Semiconductors – 80C51 Central Processing Unit (CPU)

Philips Semiconductors
8-bit microcontroller
Table 83 External clock drive XTAL1
SYMBOL
PARAMETER
t_clk
t_HIGH
t_LOW
t_r
t_f
t_CYC
oscillator clock period
HIGH time
LOW time
rise time
fall time
cycle time (12 × t_clk)
Product specification
P8xCE560
VARIABLE CLOCK
(f_clk = 3.5 to 16 MHz)
MIN.
MAX.
63
286
20
t_clk − t_LOW
20
t_clk − t_HIGH
−
20
−
20
0.75
3.4
UNIT
ns
ns
ns
ns
ns
µs
handbook, full pagewidth
t _HIGH
V _IH1
0.8 V
VIH1
0.8 V
t _LOW
tr
tf
VIH1
0.8 V
VIH1
0.8 V
t _CLK
MGA175
Fig.24 External clock drive XTAL1.
handbook, full pagewidth
2.4 V
0.45 V
2.4 V
0.45 V
2.0 V
0.8 V
test points
(a)
float
(b)
2.0 V
0.8 V
2.0 V
0.8 V
2.4 V
0.45 V
MGA174
AC testing inputs are driven at 2.4 V for a HIGH and 0.45 V for a LOW.
Timing measurements are taken at 2.0 V for a HIGH and 0.8 V for a LOW, see Fig.25 (a).
The float state is defined as the point at which a Port 0 pin sinks 3.2 mA or sources 400 µA at the voltage test levels, see Fig.25 (b).
Fig.25 AC testing input, output waveform (a) and float waveform (b).
1997 Aug 01
69