Owners manual

Interfaces
H3 Datasheet(Revision1.2) Copyright© 2015 Allwinner Technology Co.,Ltd.All Rights Reserved. Page 473
8.3.5.9. UART Modem Control Register(Default Value: 0x00000000)
Offset: 0x0010
Register Name: UART_MCR
Bit
R/W
Default/Hex
Description
31:6
/
/
/
5
R/W
0
AFCE
Auto Flow Control Enable
When FIFOs are enabled and the Auto Flow Control Enable (AFCE) bit is set,
Auto Flow Control features are enabled.
0: Auto Flow Control Mode disabled
1: Auto Flow Control Mode enabled
4
R/W
0
LOOP
Loop Back Mode
0: Normal Mode
1: Loop Back Mode
This is used to put the UART into a diagnostic mode for test purposes. If
operating in UART mode (SIR_MODE != Enabled or not active, MCR[6] set to
zero), data on the sout line is held high, while serial data output is looped
back to the sin line, internally. In this mode all the interrupts are fully
functional. Also, in loopback mode, the modem control inputs (dsr_n, cts_n,
ri_n, dcd_n) are disconnected and the modem control outputs (dtr_n, rts_n,
out1_n, out2_n) are looped back to the inputs, internally. If operating in
infrared mode (SIR_MODE == Enabled AND active, MCR[6] set to one), data
on the sir_out_n line is held low, while serial data output is inverted and
looped back to the sir_in line.
3:2
/
/
/
1
R/W
0
RTS
Request to Send
This is used to directly control the Request to Send (rts_n) output. The
Request To Send (rts_n) output is used to inform the modem or data set that
the UART is ready to exchange data. When Auto RTS Flow Control is not
enabled (MCR[5] set to zero), the rts_n signal is set low by programming
MCR[1] (RTS) to a high.In Auto Flow Control, AFCE_MODE == Enabled and
active (MCR[5] set to one) and FIFOs enable (FCR[0] set to one), the rts_n
output is controlled in the same way, but is also gated with the receiver FIFO
threshold trigger (rts_n is inactive high when above the threshold). The
rts_n signal is de-asserted when MCR[1] is set low.
0: rts_n de-asserted (logic 1)
1: rts_n asserted (logic 0)
Note that in Loopback mode (MCR[4] set to one), the rts_n output is held
inactive high while the value of this location is internally looped back to an
input.
0
R/W
0
DTR
Data Terminal Ready
This is used to directly control the Data Terminal Ready (dtr_n) output. The
confidential