Datasheet

06 February 2012 Broadcom Europe Ltd. 406 Science Park Milton Road Cambridge CB4 0WW Page 17
© 2012 Broadcom Corporation. All rights reserved
2
Enable receive
Auto flow-
control using
RTS
If this bit is set the RTS line will de-assert if the
receive FIFO reaches it 'auto flow' level. In fact the
RTS line will behave as an RTR (Ready To Receive)
line.
If this bit is clear the RTS line is controlled by the
AUX_MU_MCR_REG register bit 1.
R/W 0
1
Transmitter
enable
If this bit is set the mini UART transmitter is enabled.
If this bit is clear the mini UART transmitter is
disabled
R/W 1
0
Receiver
enable
If this bit is set the mini UART receiver is enabled.
If this bit is clear the mini UART receiver is disabled
R/W 1
Receiver enable
If this bit is set no new symbols will be accepted by the receiver. Any symbols in progress of
reception will be finished.
Transmitter enable
If this bit is set no new symbols will be send the transmitter. Any symbols in progress of
transmission will be finished.
Auto flow control
Automatic flow control can be enabled independent for the receiver and the transmitter.
CTS auto flow control impacts the transmitter only. The transmitter will not send out new
symbols when the CTS line is de-asserted. Any symbols in progress of transmission when
the CTS line becomes de-asserted will be finished.
RTS auto flow control impacts the receiver only. In fact the name RTS for the control line is
incorrect and should be RTR (Ready to Receive). The receiver will de-asserted the RTS
(RTR) line when its receive FIFO has a number of empty spaces left. Normally 3 empty
spaces should be enough.
If looping back a mini UART using full auto flow control the logic is fast enough to allow
the RTS auto flow level of '10' (De-assert RTS when the receive FIFO has 1 empty space
left).
Auto flow polarity
To offer full flexibility the polarity of the CTS and RTS (RTR) lines can be programmed.
This should allow the mini UART to interface with any existing hardware flow control
available.