Command Register A Format - Digital Equipment VAXstation I Service Manual

PROGRAMMIRG IRFOIUIATION
2.1.6.S
Command Register A - All the bits in this UART register
are write access only.
15
08 07 06 04 03 02 01 00
+·. - .. - .. - . - - ... - - ... - ......... ·+·. ·+· ••. - - - - - - -+-. -+- - ·+· - ·+· - ·+
I
not used
I
0 !MIS COMMANDIDTXIETXIDRXIERXI
+- -- - . - - • - - •... - .. - - - • - - . - - . - •• ·+-. -+- - •• - - - - •• ·+·.
·+-.
·+- - -+- - ·+
ADDRESS
=
CSR BASE
+
36
Figure 2·10: Command Register A Format
Table 2·14: Command Register A Bits
+· - ..... ·+· ...... ·+- - . - - .. - - ..
~
- - - - .. - - .... - .. - - . - .... - . - - - • - - . ·+
I
BITS
i ACCESS i DESCRIPTION
+·. - . - - • -+- - .. - - - -+- - - - - - - - - - - - • - - • - • - •••••• - - •••• - • - • - - •••••• - -+
<15:08> (not used)
<07> WRITE
<06:04>
WRITE
<03>
WRITE
<02>
WRITE
<02>
WRITE
<00> WRITE
(spare - must be zero).
Miscellaneous commands:
000 NOP (no operation)
001 Reset mode register pointer. Causes the
Mode Register pointer to point to
register l.
010 Reset receiver
011 Reset transmitter
100 Reset error status. Clears error status
bits <07:04> in Status/Clock Select
Register.
101 Reset channel A break-change interrupt.
Clears Interrupt Status/Mask Register bit
<02>.
110 Start break
111 Stop break
Disable Transmitter (1 •yes).
Enable Transmitter (1 •yes).
Disable Receiver (1 =yes).
Enable Receiver (1 =yes).
+· - •...•
-+· . . . . . ·+- - - ... - .............•..... - ...•.... - - ...... - ·+
2-15