Datasheet
RL78/L12 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0330EJ0200 Rev.2.00 411
Dec 13, 2013
The channels supporting 3-wire serial I/O (CSI00, CSI01) are channels 0 and 1.
Channel Used as CSI Used as UART
0 CSI00 UART0 (supporting LIN-bus)
1 CSI01
3-wire serial I/O (CSI00, CSI01) performs the following seven types of communication operations.
• Master transmission (See 12.5.1.)
• Master reception (See 12.5.2.)
• Master transmission/reception (See 12.5.3.)
• Slave transmission (See 12.5.4.)
• Slave reception (See 12.5.5.)
• Slave transmission/reception (See 12.5.6.)
• SNOOZE mode function (See 12.5.7.)
12.5.1 Master transmission
Master transmission is that the RL78/L12 outputs a transfer clock and transmits data to another device.
3-Wire Serial I/O CSI00 CSI01
Target channel Channel 0 Channel 1
Pins used SCK00, SO00 SCK01, SO01
Interrupt INTCSI00 INTCSI01
Transfer end interrupt (in single-transfer mode) or buffer empty interrupt (in continuous transfer mode)
can be selected.
Error detection flag None
Transfer data length 7 or 8 bits
Transfer rate Max. fMCK/2 [Hz] (CSI00), fMCK/4 [Hz] (CSI01)
Min. f
CLK/(2 × 2
15
× 128) [Hz]
Note
fCLK: System clock frequency
Data phase Selectable by the DAPmn bit of the SCRmn register
• DAPmn = 0: Data output starts from the start of the operation of the serial clock.
• DAPmn = 1: Data output starts half a clock before the start of the serial clock operation.
Clock phase Selectable by the CKPmn bit of the SCRmn register
• CKPmn = 0: Non-reverse (data output at the falling edge and data input at the rising edge of SCK)
• CKPmn = 1: Reverse (data output at the rising edge and data input at the falling edge of SCK)
Data direction MSB or LSB first
Note Use this operation within a range that satisfies the conditions above and the Peripheral functions characteristics in
the electrical specifications (see CHAPTER 30 ELECTRICAL SPECIFICATIONS (A, G: T
A = -40 to +85°C) and
CHAPTER 31 ELECTRICAL SPECIFICATIONS (G: T
A = -40 to +105°C)).
Remark m: Unit number (m = 0), n: Channel number (n = 0, 1), mn = 00, 01