Datasheet

118
4235K–8051–05/08
AT89C51RD2/ED2
25.3.2 External Program Memory Characteristics
Table 25-1. Symbol Description
Table 25-2. AC Parameters for a Fix Clock
Symbol Parameter
T Oscillator clock period
T
LHLL
ALE pulse width
T
AVLL
Address Valid to ALE
T
LLAX
Address Hold After ALE
T
LLIV
ALE to Valid Instruction In
T
LLPL
ALE to PSEN
T
PLPH
PSEN Pulse Width
T
PLIV
PSEN to Valid Instruction In
T
PXIX
Input Instruction Hold After PSEN
T
PXIZ
Input Instruction Float After PSEN
T
AVIV
Address to Valid Instruction In
T
PLAZ
PSEN Low to Address Float
Symbol -M Units
Min Max
T 25 ns
T
LHLL
35 ns
T
AVLL
5 ns
T
LLAX
5 ns
T
LLIV
n 65 ns
T
LLPL
5 ns
T
PLPH
50 ns
T
PLIV
30 ns
T
PXIX
0 ns
T
PXIZ
10 ns
T
AVIV
80 ns
T
PLAZ
10 ns