
P89V52X2_3
NXP B.V. 2009. All rights reserved.
Product data sheet
Rev. 03 — 4 May 2009
48 of 57
NXP Semiconductors
P89V52X2
80C51 with 256 B RAM, 192 B data EEPROM
Table 46.
External clock drive
Symbol
Parameter
Oscillator
Unit
40 MHz
Variable
Min
Max
Min
Max
fosc
oscillator frequency
-
0
40
MHz
Tcy(clk)
clock cycle time
25
-
ns
tCHCX
clock HIGH time
8.75
-
0.35Tcy(clk)
0.65Tcy(clk)
ns
tCLCX
clock LOW time
8.75
-
0.35Tcy(clk)
0.65Tcy(clk)
ns
tCLCH
clock rise time
-
10
-
ns
tCHCL
clock fall time
-
10
-
ns
Fig 24. External clock drive waveform (with an amplitude of at least Vi(RMS) = 200 mV)
tCHCL
tCLCX
tCHCX
Tcy(clk)
tCLCH
002aaa907
Table 47.
Serial port timing
Symbol
Parameter
Oscillator
Unit
40 MHz
Variable
Min
Max
Min
Max
TXLXL
serial port clock cycle time
0.3
-
12Tcy(clk)
-
s
tQVXH
output data set-up to clock rising
edge time
117
-
10Tcy(clk) 133
-
ns
tXHQX
output data hold after clock rising
edge time
0-
2Tcy(clk) 15
-
ns
tXHDX
input data hold after clock rising
edge time
0-
0
-
ns
tXHDV
input data valid to clock rising edge
time
-
117
-
10Tcy(clk) 133 ns