Datasheet

V850ES/JG3 CHAPTER 15 ASYNCHRONOUS SERIAL INTERFACE A (UARTA)
R01UH0015EJ0300 Rev.3.00 Page 453 of 870
Sep 30, 2010
15.4 Registers
(1) UARTAn control register 0 (UAnCTL0)
The UAnCTL0 register is an 8-bit register that controls the UARTAn serial transfer operation.
This register can be read or written in 8-bit or 1-bit units.
Reset sets this register to 10H.
(1/2)
UAnPWR
Disable UARTAn operation (UARTAn reset asynchronously)
Enable UARTAn operation
UAnPWR
0
1
UARTAn operation control
UAnCTL0
(n = 0 to 2)
UAnTXE UAnRXE UAnDIR UAnPS1 UAnPS0 UAnCL UAnSL
<6> <5> <4> 3 2 1
After reset: 10H R/W Address:
UA0CTL0 FFFFFA00H, UA1CTL0 FFFFFA10H,
UA2CTL0 FFFFFA20H
The UARTAn operation is controlled by the UAnPWR bit. The TXDAn pin output
is fixed to high level by clearing the UAnPWR bit to 0 (fixed to low level if
UAnOPT0.UAnTDL bit = 1).
Disable transmission operation
Enable transmission operation
UAnTXE
0
1
Transmission operation enable
• To start transmission, set the UAnPWR bit to 1 and then set the UAnTXE bit to 1.
To stop, transmission clear the UAnTXE bit to 0 and then UAnPWR bit to 0.
• To initialize the transmission unit, clear the UAnTXE bit to 0, wait for two cycles of
the base clock, and then set the UAnTXE bit to 1 again. Otherwise, initialization
may not be executed (for the base clock, see 15.7 (1) (a) Base clock).
Disable reception operation
Enable reception operation
UAnRXE
0
1
Reception operation enable
• To start reception, set the UAnPWR bit to 1 and then set the UAnRXE bit to 1.
To stop reception, clear the UAnRXE bit to 0 and then UAnPWR bit to 0.
• To initialize the reception unit, clear the UAnRXE bit to 0, wait for two periods of
the base clock, and then set the UAnRXE bit to 1 again. Otherwise, initialization
may not be executed (for the base clock, see 15.7 (1) (a) Base clock).
<7> 0