t89c51rd2-slscl ATMEL Corporation, t89c51rd2-slscl Datasheet - Page 85

• Manufacturer Part Number: t89c51rd2-slscl
• Description: 0 To 40 Mhz Flash Programmable 8-bit Microcontroller
• Manufacturer: ATMEL Corporation

AC Parameters
Explanation of the AC
Symbols
4243G–8051–05/03
Figure 35. I
Figure 36. Clock Signal Waveform for I
Each timing symbol has 5 characters. The first character is always a “T” (stands for
time). The other characters, depending on their positions, stand for the name of a signal
or the logical status of that signal. The following is a list of all the characters and what
they stand for.
Example:T
T
T
T
T
AC characteristics of -M parts at 3 volts are similar to -L parts
(Load Capacitance for port 0, ALE and PSEN = 100 pF; Load Capacitance for all other
outputs = 80 pF.)
Table 44, Table 48 and Table 50 give the description of each AC symbols.
Table 46, Table 49 and Table 51 give for each range the AC parameter.
Table 47, Table 50 and Table 52 give the frequency derating formula of the AC parame-
ter for each speed range description. To calculate each AC symbols. take the x value in
the correponding column (-M or -L) and use this value in the formula.
Example: T
x = 35 ns
T = 50 ns
T
A
A
A
A
CCIV
T
= 0 to +70°C; V
= -40°C to +85°C; V
= 0 to +70°C; V
= -40°C to +85°C; V
LLPL
= 4T - x = 165 ns
= Time for ALE Low to PSEN Low.
AVLL
LLIU
(NC)
CC
= Time for Address Valid to ALE Low.
for -M and 20 MHz, Standard clock.
Test Condition, Power-Down Mode
SS
SS
V
= 0 V; V
= 0 V; 2.7 V < V
RST
XTAL2
XTAL1
V
CC
SS
SS
SS
T
-0.5V
0.45V
CHCL
= 0 V; V
= 0 V; 2.7 V < V
T
V
CLCH
EA
CC
I
CC
P0
CC
= T
V
= 5 V ± 10%; M range.
CC
CC
V
CHCL
CC
CC
= 5 V ± 10%; M range.
= 5ns.
CC
T
< 3.3 V; L range.
CLCH
CC
Tests in Active and Idle Modes
< 3.3 V; L range.
0.7V
0.2V
CC
CC
All other pins are disconnected.
-0.1
T89C51RD2
85