Operation Of Serial Interface Uart6; Operation Stop Mode - NEC 78K0/KD1 Series User Manual

14.4 Operation of Serial Interface UART6

This section explains the two modes of serial interface UART6.

14.4.1 Operation stop mode

In this mode, serial transfer cannot be executed; therefore, the power consumption can be reduced. In addition,
the pins can be used as ordinary port pins in this mode.
(1) Register setting
The operation stop mode is set by asynchronous serial interface operation mode register 6 (ASIM6).
ASIM6 can be set by a 1-bit or 8-bit memory manipulation instruction.
RESET input sets this register to 01H.
Remark ASIM6 can be refreshed (the same value is written) by software during a communication operation
(when bit 7 (POWER6) and bit 6 (TXE6) of ASIM6 = 1 or bit 7 (POWER6) and bit 5 (RXE6) of ASIM6
= 1).
Address: FF50H After reset: 01H R/W
Symbol 7
ASIM6 POWER6
POWER6
Note 1
0
Note 2
1
TXE6
0
1
RXE6
0
1
Notes 1. The output of the T
POWER6 = 0.
2. Operation of the internal operation clock is enabled at the second input clock after 1 is written to the
POWER6 bit.
Cautions 1. At startup, set POWER6 to 1 and then set TXE6 to 1. Clear TXE6 to 0 first, and then clear
POWER6 to 0.
2. At startup, set POWER6 to 1 and then set RXE6 to 1. Clear RXE6 to 0 first, and then clear
POWER6 to 0.
CHAPTER 14 SERIAL INTERFACE UART6
6 5
TXE6 RXE6
Enables/disables operation of internal operation clock
Disables operation of the internal operation clock (fixes the clock to low level) and asynchronously
resets the internal circuit.
Enables operation of the internal operation clock.
Disables transmission operation (synchronously resets the transmission circuit).
Enables transmission
Disables reception (synchronously resets the reception circuit).
Enables reception
D6 pin goes high and the input from the R
X
Preliminary User's Manual U16315EJ1V0UD
4 3
PS61 PS60
Enables/disables transmission
Enables/disables reception
D6 pin is fixed to the high level when
X
2 1 0
CL SL6 ISRM6
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