AT80C51RD2 Atmel Corporation, AT80C51RD2 Datasheet - Page 38

• 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

11.3.1
Figure 11-5. Internal Baud Rate
38
AT80C51RD2
Internal Baud Rate Generator (BRG)
Peripheral clock
BRR
Table 11-3.
When the internal Baud Rate Generator is used, the Baud Rates are determined by the BRG
overflow depending on the BRL reload value, the value of SPD bit (Speed Mode) in BDRCON
register and the value of the SMOD1 bit in PCON register.
• The baud rate for UART is token by formula:
(T2CON)
BaudRate
(
TCLK
BRL
X
X
X
0
1
0
1
0
1
)
=
Baud Rate Selection Table UART
/6
256
=
--------------------------------------------------------------------------------------------------------- -
2
–
(T2CON)
×
---------------------------------------------------------------------------------------- -
2
RCLK
2
×
X
X
X
0
0
1
1
0
1
SPD
×
0
1
2
6
2
×
auto reload counter
〈
SMOD1
2
6
1 SPD
SMOD
(
–
1 SPD
–
×
(BDRCON)
×
〉
F
)
F
BRG
BRL
TBCK
×
×
CLKPERIPH
CLKPERIPH
0
0
0
0
1
1
0
0
1
16
16
×
×
overflow
[
BaudRate
256
–
(BDRCON)
(
BRL
RBCK
0
0
0
0
0
0
1
1
1
)
]
/2
Clock Source
0
1
INT_BRG
INT_BRG
INT_BRG
UART Tx
Timer 1
Timer 2
Timer 1
Timer 2
Timer 1
Timer 2
INT_BRG
4113D–8051–01/09
Clock Source
UART Rx
INT_BRG
INT_BRG
INT_BRG
Timer 1
Timer 1
Timer 2
Timer 2
Timer 1
Timer 2