Operations; Initialization; Data Transmission - Epson S1C17W03 Technical Manual

12 UART (UART)
UAnMOD register
CHLN bit STPB bit
0 0
0 0
0 1
0 1
1 0
1 0
1 1
1 1

12.5 Operations

12.5.1 Initialization

The UART Ch.n should be initialized with the procedure shown below.
1. Assign the UART Ch.n input/output function to the ports. (Refer to the "I/O Ports" chapter.)
2. Set the UAnCLK.CLKSRC[1:0] and UAnCLK.CLKDIV[1:0] bits. (Configure operating clock)
3. Configure the following UAnMOD register bits:
- UAnMOD.PUEN bit
- UAnMOD.OUTMD bit (Enable/disable USOUTn pin open-drain output)
- UAnMOD.IRMD bit
- UAnMOD.CHLN bit
- UAnMOD.PREN bit
- UAnMOD.PRMD bit
- UAnMOD.STPB bit
4. Set the UAnBR.BRT[7:0] and UAnBR.FMD[3:0] bits.
5. Set the following UAnCTL register bits:
- Set the UAnCTL.SFTRST bit to 1.
- Set the UAnCTL.MODEN bit to 1.
6. Set the following bits when using the interrupt:
- Write 1 to the interrupt flags in the UAnINTF register.
- Set the interrupt enable bits in the UAnINTE register to 1. * (Enable interrupts)
* The initial value of the UAnINTF.TBEIF bit is 1, therefore, an interrupt will occur immediately after the UA-
nINTE.TBEIE bit is set to 1.

12.5.2 Data Transmission

A data sending procedure and the UART Ch.n operations are shown below. Figures 12.5.2.1 and 12.5.2.2 show a
timing chart and a flowchart, respectively.
Data sending procedure
1. Check to see if the UAnINTF.TBEIF bit is set to 1 (transmit buffer empty).
2. Write transmit data to the UAnTXD register.
3. Wait for a UART interrupt when using the interrupt.
4. Repeat Steps 1 to 3 (or 1 and 2) until the end of transmit data.
12-4
PREN bit
0 st D0
1
st D0
0 st D0
1 st D0
0 st D0
1 st D0
0
st D0
1 st D0
Figure 12.4.1 Data Format
(Enable/disable USINn pin pull-up)
(Enable/disable IrDA interface)
(Set 7/8-bit data length)
(Enable/disable parity function)
(Even/odd parity selection)
(Set 1/2-bit stop bit length)
Seiko Epson Corporation
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
D1 D2 D3 D4 D5
st: start bit, sp: stop bit, p: parity bit
(Set transfer rate)
(Execute software reset)
(Enable UART Ch.n operations)
(Clear interrupt flags)
S1C17W03/W04 TECHNICAL MANUAL
D6 sp
D6 p sp
D6 sp sp
D6 p sp sp
D6 D7 sp
D6 D7 p sp
D6 D7 sp sp
D6 D7 p sp sp
(Rev. 1.2)