Datasheet

RL78/L12 CHAPTER 12 SERIAL ARRAY UNIT
R01UH0330EJ0200 Rev.2.00 410
Dec 13, 2013
12.5 Operation of 3-Wire Serial I/O (CSI00, CSI01) Communication
This is a clocked communication function that uses three lines: serial clock (SCK) and serial data (SI and SO) lines.
[Data transmission/reception]
• Data length of 7 or 8 bits
• Phase control of transmit/receive data
• MSB/LSB first selectable
[Clock control]
• Master/slave selection
• Phase control of I/O clock
• Setting of transfer period by prescaler and internal counter of each channel
• Maximum transfer rate
During master communication (CSI00): Max. f
MCK/2
Notes 1, 2
During master communication (CSI01): Max. fMCK/4
Note 2
During slave communication: Max. f
MCK/6
Note 2
[Interrupt function]
• Transfer end interrupt/buffer empty interrupt
[Error detection flag]
• Overrun error
In addition, CSI00 supports the SNOOZE mode. When SCK input is detected while in the STOP mode, the SNOOZE
mode makes data reception that does not require the CPU possible.
Notes 1. In master communication (CSI00), maximum transfer rate become f
MCK/2 when the following conditions.
• 2.7 V ≤ EV
DD = VDD ≤ 5.5 V
• fMCK ≤ 12 MHz
Other cases, maximum transfer rate become f
MCK/4.
2. Use the clocks within a range satisfying the SCK cycle time (t
KCY) characteristics (see CHAPTER 30
ELECTRICAL SPECIFICATIONS (A, G: TA = -40 to +85°C) and CHAPTER 31 ELECTRICAL
SPECIFICATIONS (G: T
A = -40 to +105°C)).
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