Controlling Data Transmission/Reception - Epson S1C17704 Technical Manual

21.5 Controlling Data Transmission/Reception

Before starting data transfer, set up the conditions by the procedure below.
(1) Configure the carrier signal. See Section 21.3.
(2) Select a clock for the data length counter. See Section 21.4.
(3) Set up the interrupt conditions. See Section 21.6.
Note: Make sure that the REMC module is disabled (REMEN/REMC_CFG register = 0) before setting
the conditions above.
∗ REMEN: REMC Enable Bit in the REMC Configuration (REMC_CFG) Register (D0/0x5340)
Data transmit control
REMDT
REMO pin output
Carrier
REMDT
REMO pin output
PSC output clock
(Data length counter clock)
REMLEN[7:0]
Interrupt signal
(1) Setting data transmit mode
Write 0 to REMMD (D1/REMC_CFG register) to set the REMC in data transmit mode.
∗ REMMD: REMC Mode Select Bit in the REMC Configuration (REMC_CFG) Register (D1/0x5340)
(2) Enabling data transmission
Set REMEN (D0/REMC_CFG register) to 1 to enable the REMC operation. This makes the REMC start the
data transmit operation.
To prevent unnecessary data from being transmitted, set REMDT (D0/REMC_ST register) to 0 and
REMLEN[7:0] (D[7:0]/REMC_LCNT register) to 0x0 before writing 1 to REMEN.
(3) Setting transmit data
Set data to be transmitted (high or low) to REMDT (D0/REMC_ST register).
∗ REMDT: Transmit/Receive Data Bit in the REMC Status (REMC_ST) Register (D0/0x5344)
Setting REMDT to 1 specifies high output; setting it to 0 specifies low output. The specified data is modulated
with the carrier signal and output from the REMO pin.
(4) Setting the data pulse width
Write the value equivalent to the pulse width (high period or low period) of the transmit data to REMLEN[7:0]
(D[7:0]/REMC_LCNT register) to set it to the data length counter.
∗ REMLEN[7:0]: Transmit/Receive Data Length Count Bits in the REMC Length Counter (REMC_LCNT)
Register (D[7:0]/0x5345)
S1C17704 TECHNICAL MANUAL
Figure 21.5.1 Data Transmission
PCLK
4
Figure 21.5.2 Underflow Interrupt Generation Timing
EPSON
21 REMOTE CONTROLLER (REMC)
3 2 1 0
21-5