AT89C51RC2-3CSCM View Datasheet(PDF) - Atmel Corporation
Part Name
Description
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AT89C51RC2-3CSCM Datasheet PDF : 127 Pages
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Table 32. Baud Rate Selection Table UART
TCLK
(T2CON)
0
RCLK
(T2CON)
0
TBCK
(BDRCON)
0
RBCK
(BDRCON)
0
1
0
0
0
0
1
0
0
1
1
0
0
X
0
1
0
X
1
1
0
0
X
0
1
1
X
0
1
X
X
1
1
Clock Source Clock Source
UART Tx
UART Rx
Timer 1
Timer 1
Timer 2
Timer 1
Timer 1
Timer 2
Timer 2
Timer 2
INT_BRG
Timer 1
INT_BRG
Timer 2
Timer 1
INT_BRG
Timer 2
INT_BRG
INT_BRG
INT_BRG
Internal Baud Rate Generator
(BRG)
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.
Figure 21. Internal Baud Rate
FClk Periph
÷6
0
1
SPD
BDRCON.1
BRR
BDRCON.4
BRG
(8 bits)
Overflow
÷2
0
1
BRL
(8 bits)
SMOD1
PCON.7
INT_BRG
• The baud rate for UART is token by formula:
Baud_Rate =
2SMOD1 ⋅ FPER
6(1-SPD) ⋅ 32 ⋅ (256 -BRL)
BRL = 256 -
2SMOD1 ⋅ FPER
6(1-SPD) ⋅ 32 ⋅ Baud_Rate
48 AT89C51RB2/RC2
4180E–8051–10/06
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