AT89C51-24JC Atmel, AT89C51-24JC Datasheet - Page 6
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AT89C51-24JC
Manufacturer Part Number
AT89C51-24JC
Description
IC MICRO CTRL 24MHZ 44PLCC
Manufacturer
Atmel
Series
89Cr
Datasheet
1.AT89C51-24AC.pdf
(17 pages)
Specifications of AT89C51-24JC
Core Processor
8051
Core Size
8-Bit
Speed
24MHz
Connectivity
UART/USART
Number Of I /o
32
Program Memory Size
4KB (4K x 8)
Program Memory Type
FLASH
Ram Size
128 x 8
Voltage - Supply (vcc/vdd)
4 V ~ 6 V
Oscillator Type
Internal
Operating Temperature
0°C ~ 70°C
Package / Case
44-PLCC
Data Bus Width
8 bit
Data Ram Size
128 B
Maximum Clock Frequency
24 MHz
Number Of Programmable I/os
32
Number Of Timers
2
Operating Supply Voltage
0 V to 6.6 V
Maximum Operating Temperature
+ 70 C
Mounting Style
SMD/SMT
Minimum Operating Temperature
0 C
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Eeprom Size
-
Data Converters
-
Peripherals
-
Lead Free Status / Rohs Status
No
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
AT89C51-24JC
Manufacturer:
ATMEL
Quantity:
8 766
Part Number:
AT89C51-24JC
Manufacturer:
ATMEL/爱特梅尔
Quantity:
20 000
Programming the Flash
The AT89C51 is normally shipped with the on-chip Flash
memory array in the erased state (that is, contents = FFH)
and ready to be programmed. The programming interface
accepts either a high-voltage (12-volt) or a low-voltage
(V
ming mode provides a convenient way to program the
AT89C51 inside the user’s system, while the high-voltage
programming mode is compatible with conventional third-
party Flash or EPROM programmers.
The AT89C51 is shipped with either the high-voltage or
low-voltage programming mode enabled. The respective
top-side marking and device signature codes are listed in
the following table.
The AT89C51 code memory array is programmed byte-by-
byte in either programming mode. To program any non-
blank byte in the on-chip Flash Memory, the entire memory
must be erased using the Chip Erase Mode.
Programming Algorithm: Before programming the
AT89C51, the address, data and control signals should be
set up according to the Flash programming mode table and
Figure 3 and Figure 4. To program the AT89C51, take the
following steps.
1. Input the desired memory location on the address
2. Input the appropriate data byte on the data lines.
3. Activate the correct combination of control signals.
4. Raise EA/V
5. Pulse ALE/PROG once to program a byte in the
6
Top-side Mark
Signature
CC
lines.
ming mode.
Flash array or the lock bits. The byte-write cycle is
self-timed and typically takes no more than 1.5 ms.
Repeat steps 1 through 5, changing the address
) program enable signal. The low-voltage program-
PP
to 12V for the high-voltage program-
V
AT89C51
xxxx
yyww
(030H) = 1EH
(031H) = 51H
(032H) =F FH
PP
= 12V
AT89C51
V
AT89C51
xxxx-5
yyww
(030H) = 1EH
(031H) = 51H
(032H) = 05H
PP
= 5V
Data Polling: The AT89C51 features Data Polling to indi-
cate the end of a write cycle. During a write cycle, an
attempted read of the last byte written will result in the com-
plement of the written datum on PO.7. Once the write cycle
has been completed, true data are valid on all outputs, and
the next cycle may begin. Data Polling may begin any time
after a write cycle has been initiated.
Ready/Busy: The progress of byte programming can also
be monitored by the RDY/BSY output signal. P3.4 is pulled
low after ALE goes high during programming to indicate
BUSY. P3.4 is pulled high again when programming is
done to indicate READY.
Program Verify: If lock bits LB1 and LB2 have not been
programmed, the programmed code data can be read back
via the address and data lines for verification. The lock bits
cannot be verified directly. Verification of the lock bits is
achieved by observing that their features are enabled.
Chip Erase: The entire Flash array is erased electrically
by using the proper combination of control signals and by
holding ALE/PROG low for 10 ms. The code array is written
with all “1”s. The chip erase operation must be executed
before the code memory can be re-programmed.
Reading the Signature Bytes: The signature bytes are
read by the same procedure as a normal verification of
locations 030H, 031H, and 032H, except that P3.6 and
P3.7 must be pulled to a logic low. The values returned are
as follows.
Programming Interface
Every code byte in the Flash array can be written and the
entire array can be erased by using the appropriate combi-
nation of control signals. The write operation cycle is self-
timed and once initiated, will automatically time itself to
completion.
All major programming vendors offer worldwide support for
the Atmel microcontroller series. Please contact your local
programming vendor for the appropriate software revision.
and data for the entire array or until the end of the
object file is reached.
(030H) = 1EH indicates manufactured by Atmel
(031H) = 51H indicates 89C51
(032H) = FFH indicates 12V programming
(032H) = 05H indicates 5V programming