AT80C51RD2 Atmel Corporation, AT80C51RD2 Datasheet - Page 66

• Manufacturer Part Number: AT80C51RD2
• Manufacturer: Atmel Corporation

Specifications of AT80C51RD2

• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 32
• Spi: 1
• Uart: 1
• Sram (kbytes): 1.25
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Watchdog: Yes

17.3
17.3.1
4113D–8051–01/09
AC Parameters
Explanation of the AC Symbols
Figure 17-4. 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 sta-
tus of that signal. The following is a list of all the characters and what they stand for.
Example:T
(Load Capacitance for port 0, ALE and PSEN = 100 pF; Load Capacitance for all other outputs =
80 pF.)
Table 17-2 Table 17-5, and Table 17-7 give the description of each AC symbols.
Table 17-4, Table 17-6 and Table 17-8 give for each range the AC parameter.
Table 17-3, Table 17-4 and Table 17-9 gives 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 and use this value in the formula.
Example: T
x = 35 ns
T = 50 ns
T
CCIV
= 4T - x = 165 ns
T
LLPL
AVLL
LLIU
= Time for ALE Low to PSEN Low.
V
= Time for Address Valid to ALE Low.
for 20 MHz, Standard clock.
CC
T
-0.5V
0.45V
CHCL
T
CLCH
= T
CHCL
= 5ns.
T
CLCH
0.7V
0.2V
CC
CC
CC
Tests in Active and Idle Modes
-0.1
AT80C51RD2
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