UART

S3C84E5/C84E9/P84E9

 

 

UART MODE 1 FUNCTION DESCRIPTION

In mode 1, 10-bits are transmitted (through the TxD (P1.5) pin) or received (through the RxD (P1.4) pin). Each data frame has three components:

Start bit ("0")

8 data bits (LSB first)

Stop bit ("1")

When receiving, the stop bit is written to the RB8 bit in the UARTCON register. The baud rate for mode 1 is variable.

Mode 1 Transmit Procedure

1.Select the baud rate generated by 16bit BRDATA.

2.Select mode 1 (8-bit UART) by setting UARTCON bits 7 and 6 to '01B'.

3.Write transmission data to the shift register UDATA (F5H). The start and stop bits are generated automatically by hardware.

Mode 1 Receive Procedure

1.Select the baud rate to be generated by 16-bit BRDATA.

2.Select mode 1 and set the RE (Receive Enable) bit in the UARTCON register to "1".

3.The start bit low ("0") condition at the RxD (P1.4) pin will cause the UART module to start the serial data receive operation.

Tx

Clock

 

Write to Shift Register (UDATA)

 

 

 

 

 

 

 

Shift

 

 

 

 

 

 

 

 

 

 

TxD

Start Bit

D0

D1

D2

D3

D4

D5

D6

D7

Stop Bit

TIP

 

 

 

 

 

 

 

 

 

 

Transmit

Rx

Clock

RxD

Start Bit

D0

D1

D2

D3

D4

D5

D6

Bit Detect Sample Time

Shift

RIP

 

D7

 

 

Stop Bit

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Receive

Figure 13-7. Timing Diagram for UART Mode 1 Operation

13-10

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Samsung S3C84E5 user manual Uart Mode 1 Function Description, Mode 1 Transmit Procedure, Mode 1 Receive Procedure, 13-10