AT89C51RC2 Atmel Corporation, AT89C51RC2 Datasheet - Page 98

• Manufacturer Part Number: AT89C51RC2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RC2

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

Autobaud Performances
Command Data Stream
Protocol
98
Table 72. Autobaud Performances
AT89C51RB2/RC2
Frequency (MHz)
Baudrate (bit/s)
2400
4800
9600
19200
38400
57600
115200
Frequency (MHz)
Baudrate (bit/s)
2400
4800
9600
19200
38400
57600
115200
1.8432
OK
OK
OK
OK
10
OK
OK
OK
OK
-
-
-
-
-
-
The ISP feature allows a wide range of baud rates in the user application. It is also
adaptable to a wide range of oscillator frequencies. This is accomplished by measuring
the bit-time of a single bit in a received character. This information is then used to pro-
gram the baud rate in terms of timer counts based on the oscillator frequency. The ISP
f e a tu r e r e q u ir e s th a t a n in itia l c h a ra c te r (a n u p p e rc a s e U ) b e se n t t o t h e
AT89C51RB2/RC2 to establish the baud rate. Table 72 shows the autobaud capability.
All commands are sent using the same flow. Each frame sent by the host is echoed by
the bootloader.
11.0592
OK
OK
OK
OK
OK
OK
OK
OK
2
-
-
-
-
-
-
2.4576
OK
OK
OK
OK
OK
12
OK
OK
OK
OK
OK
-
-
-
-
14.318
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
3
-
-
3.6864
14.746
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
-
OK
OK
OK
16
OK
OK
OK
OK
OK
OK
4
-
-
-
-
-
OK
OK
OK
OK
20
OK
OK
OK
OK
OK
OK
5
-
-
-
-
OK
OK
OK
OK
OK
24
OK
OK
OK
OK
OK
OK
6
-
-
-
7.3728
26.6
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
OK
-
OK
OK
OK
OK
8
4180E–8051–10/06