2001 Apr 06

16

Philips Semiconductors

Preliminary specification

P87C51MB2/P87C51MC2

80C51 8-bit microcontroller family with extended memory

64KB/96KB OTP with 2KB/3KB RAM

Baud Rate Selection

UART 0 and UART 1 selects the baud rate differently as shown in Tables 4 and 5:

S0CON.7

(SM0_0)

S0CON.6

(SM1_0)

T2CON.5/4

(RCLK - Receive

TCLK - Transmit)

PCON.7

(SMOD1)

BRGCON.1

(S0BRGS)

Receive/Transmit Baud Rate for UART 0

0

0

X

X

X

0

1

0

0

X

0

1

X

1

X

0

1

X

1

*

1

0

X

0

X

X

1

X

1

1

0

0

X

0

1

X

1

X

0

1

X

1

*

*

UART 0 can have different receive and transmit baud rates.

Table 4: Baud Rate Generation for UART 0. Use T2CON.5 (RCLK) in Receive Baud Rate Selection, T2CON.4 (TCLK) in

Transmit Baud Rate Selection

S1CON.7

(SM0_1)

S1CON.6

(SM1_1)

Baud Rate for UART 1

0

0

0

1

*

1

0

*

1

1

*

*

UART 1 has the same receive and transmit baud rate.

Table 5: Baud Rate Generation for UART 1.