AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 168

• Manufacturer Part Number: AT89C51RE2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RE2

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Spi: 1
• Uart: 2
• Sram (kbytes): 8.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/OCD
• Watchdog: Yes

AC Parameters
Explanation of the AC
Symbols
168
AT89C51RE2
Figure 72. I
Figure 73. I
Figure 74. 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 119 Table 122, and Table 125 give the description of each AC symbols.
Table 120, Table 121, Table 123 and Table 126 gives the range for each AC parameter.
Table 120, Table 121 and Table 127 give the frequency derating formula of the AC parameter
for each speed range description. To calculate each AC symbols. Take the x value in the corre-
sponding column (-M or -L) and use this value in the formula.
T
LLPL
= Time for ALE Low to PSEN Low.
AVLL
CC
CC
(NC)
= Time for Address Valid to ALE Low.
Test Condition, Idle Mode
Test Condition, Power-down Mode
CLOCK
SIGNAL
(NC)
RST
XTAL2
XTAL1
V
SS
V
V
CC
V
RST
XTAL2
XTAL1
EA
CC
T
I
P0
SS
-0.5V
0.45V
CC
CHCL
V
T
CC
V
CLCH
EA
V
CC
P0
I
CC
CC
= T
CC
V
CC
CHCL
V
Tests in Active and Idle Modes
CC
= 5ns.
T
CLCH
0.7V
All other pins are disconnected.
0.2V
All other pins are disconnected.
CC
CC
-0.1
7663E–8051–10/08