RL78/F13, F14 CHAPTER 15 SERIAL ARRAY UNIT
R01UH0368EJ0210 Rev.2.10 800
Dec 10, 2015
(1) Shift register
This is a 16-bit register that converts parallel data into serial data or vice versa.
During reception, it converts data input to the serial pin into parallel data.
When data is transmitted, the value set to this register is output as serial data from the serial output pin.
The shift register cannot be directly manipulated by program.
To read or write the shift register, use the serial data register mn (SDRmn) when operation is in progress (SEmn =
1).
15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
Shift
register
(2) Serial data register mn (SDRmn)
The SDRmn register is the transmit/receive data register (16 bits) of channel n. If operation is stopped (SEmn = 0),
bits 15 to 9 are used as a register that sets the division ratio of the operation clock (f
MCK). If operation is in progress
(SEmn = 1), the SDRmn register functions as a transmit/receive buffer register.
When data is received, parallel data converted by the shift register is stored. When data is to be transmitted, set
transmit data to be transferred to the shift register .
The data to be stored is as follows, depending on the setting of bits 4 to 0 (DLSmn4 to DLSmn0) of serial
communication operation setting register mn (SCRmn), regardless of the output sequence of the data.
• 7-bit data length (stored in bits 0 to 6 of SDRmn register)
• 8-bit data length (stored in bits 0 to 7 of SDRmn register)
• 9-bit data length (stored in bits 0 to 8 of SDRmn register)
:
• 16-bit data length (stored in bits 0 to 15 of SDRmn register)
The SDRmn register can be read or written in 16-bit units.
The lower 8 bits of the SDRmn register can be read or written as the following SFR when operation is in progress
(SEmn = 1). The following SDRmnL registers are available, depending on the communication mode.
• CSIp communication … SDRpL
• UARTq reception … SDRmnL
• UARTq transmission … SDRmnL
• IICr communication … SDRrL
Reset signal generation clears the SDRmn register to 0000H.
Note Writing in 8-bit units is prohibited when the operation is stopped (SEmn = 0).
Remark m: Unit number (m = 0, 1), n: Channel number (n = 0, 1), p: CSI number (p = 00, 01, 10, 11), q: UART
number (q = 0, 1), r: IIC number (r = 00, 01, 10, 11)
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