C8051F340/1/2/3/4/5/6/7

SFR Definition 18.1. SCON0: Serial Port 0 Control

R/W

R

R/W

R/W

R/W

R/W

R/W

R/W

Reset Value

S0MODE

-

MCE0

REN0

TB80

RB80

TI0

RI0

01000000

Bit7

Bit6

Bit5

Bit4

Bit3

Bit2

Bit1

Bit0

 

Bit

Addressable

 

 

 

 

 

 

 

 

 

 

 

 

 

 

SFR Address: 0x98

Bit7:

S0MODE: Serial Port 0 Operation Mode.

 

 

 

 

 

 

This bit selects the UART0 Operation Mode.

 

 

 

 

 

 

0: 8-bit UART with Variable Baud Rate.

 

 

 

 

 

 

 

1: 9-bit UART with Variable Baud Rate.

 

 

 

 

 

 

Bit6:

UNUSED. Read = 1b. Write = don’t care.

 

 

 

 

 

Bit5:

MCE0: Multiprocessor Communication Enable.

 

 

 

 

 

 

The function of this bit is dependent on the Serial Port 0 Operation Mode.

 

 

 

 

S0MODE = 0: Checks for valid stop bit.

 

 

 

 

 

 

0: Logic level of stop bit is ignored.

 

 

 

 

 

 

1: RI0 will only be activated if stop bit is logic level 1.

 

 

 

 

 

S0MODE = 1: Multiprocessor Communications Enable.

 

 

 

 

 

0: Logic level of ninth bit is ignored.

 

 

 

 

 

 

1: RI0 is set and an interrupt is generated only when the ninth bit is logic 1.

 

Bit4:

REN0: Receive Enable.

 

 

 

 

 

 

 

 

This bit enables/disables the UART receiver.

 

 

 

 

 

 

0: UART0 reception disabled.

 

 

 

 

 

 

 

1: UART0 reception enabled.

 

 

 

 

 

 

Bit3:

TB80: Ninth Transmission Bit.

 

 

 

 

 

 

 

The logic level of this bit will be assigned to the ninth transmission bit in 9-bit UART Mode. It

 

is not used in 8-bit UART Mode. Set or cleared by software as required.

 

 

 

Bit2:

RB80: Ninth Receive Bit.

 

 

 

 

 

 

 

 

RB80 is assigned the value of the STOP bit in Mode 0; it is assigned the value of the 9th

 

data bit in Mode 1.

 

 

 

 

 

 

 

Bit1:

TI0: Transmit Interrupt Flag.

 

 

 

 

 

 

 

Set by hardware when a byte of data has been transmitted by UART0 (after the 8th bit in

 

8-bit UART Mode, or at the beginning of the STOP bit in 9-bit UART Mode). When the

 

 

UART0 interrupt is enabled, setting this bit causes the CPU to vector to the UART0 interrupt

 

service routine. This bit must be cleared manually by software.

 

 

 

Bit0:

RI0: Receive Interrupt Flag.

 

 

 

 

 

 

 

 

Set to ‘1’ by hardware when a byte of data has been received by UART0 (set at the STOP bit

 

sampling time). When the UART0 interrupt is enabled, setting this bit to ‘1’ causes the CPU

 

to vector to the UART0 interrupt service routine. This bit must be cleared manually by soft-

 

ware.

 

 

 

 

 

 

 

 

216

Rev. 0.5

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Image 216
Silicon Laboratories C8051F347, C8051F346 SFR Definition 18.1. SCON0 Serial Port 0 Control, S0MODE MCE0 REN0, TI0 RI0