AP513 ACROPACK
USER
’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 24 -
http://www.acromag.com
- 24 -
www.acromag.com
3.2.6 SLEEP[31:24] (default 0x00)
The 8-bit SLEEP register enables each UART separately to enter Sleep mode.
The SLEEP register is accessible from the Device Configuration Registers in
all UART channels but the UART channel can only control the bit for that
channel. For example, writing 0xFF to the SLEEP register in channel 0 will
only enable the sleep mode for channel 0. Sleep mode reduces power
consumption when the system needs to put the UART(s) to idle. The UART
enters sleep mode when the following conditions are satisfied after the
sleep mode is enabled (Logic 0 (default) is to disable and logic 1 is to enable
sleep mode):
•
Transmitter and Receiver are empty (LSR[6]=1, LSR[0]=0)
•
RX pin is idling at a HIGH in normal mode
•
The modem input (CTS#) is steady at either HIGH or LOW (MSR bits
[3:0] = 0x0)
The XR17V354 is awakened by any of the following events occurring at any
of the 4 UART channels:
•
A receive data start bit transition (HIGH to LOW in normal mode)
•
A data byte is loaded into the transmitter
•
A change of logic state on any of the modem inputs so that any of
the delta bits (MSR bits[3:0]) is set
A receive data start bit transition will not wake up the UART if the Multidrop
mode is disabled (DLD[6] = 0) and the receiver is disabled (MSR[2] = 1,
MSR[0] = 0).
A special interrupt is generated with an indication of no pending interrupt.
The XR17V354 will return to sleep mode automatically after all interrupting
conditions have been serviced and cleared. It will stay in the sleep mode of
operation until it is disabled by resetting the SLEEP register bits.
3.2.7 DVID[15:8]
Device identification for the type of UART. The Device ID of the XR17V354 is
0x84.
3.2.8 DREV[7:0]
Revision number of the XR17V354. A 0x01 represents "revision-A" with 0x02
for rev-B and so on.
3.2.9 REGB[23:16] (default 0x00)
REGB register provides a control for simultaneous write to all 4 UARTs
configuration register or individually. This is very useful for device
initialization in the power up and reset routines.
Table 3.7 REGB Register
REGB[23:19]
Not Used.
