AP513 ACROPACK
USER
’S MANUAL
Acromag, Inc. Tel: 248-295-0310
- 23 -
http://www.acromag.com
- 23 -
www.acromag.com
•
Any write to TIMER MSB, LSB registers
•
Issue of any command other than
’
Stop Timer
’
and
’
Reset Timer
’
(
’
Start Timer
’
is not allowed)
Timer Interrupt:
In the one-shot mode, the Timer will issue an interrupt upon timing out
which is ’N’ clocks after the Timer is started. In the re
-triggerable mode, the
Timer will keep issuing an interrupt every ’N’ clocks which is on every rising
edge of the Timer output. The Timer interrupt can be cleared by reading the
TIMERCNTL register or when a Timer Reset command is issued which brings
the Timer back to its default settings. The TIMERCNTL will read a value of
0x01 when the Timer interrupt is enabled and there is a pending interrupt. It
reads a value of 0x00 at all other times. Stopping the Timer does not clear
the interrupt and neither does subsequent restarting.
3.2.3 8XMODE[7:0] (default 0x00)
Each bit selects 8X or 16X sampling rate for that UART channel. The
8XMODE 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, bit [0] is for channel 0 and can only be controlled by
channel 0. All other bits are read-only in channel 0. Logic 0 (default) selects
normal 16X sampling (with 4XMODE = 0x00) and logic one selects 8X
sampling rate. Transmit and receive data rates will double by selecting 8X. If
using the 4XMODE, the corresponding bit in this register should be logic 0.
3.2.4 4XMODE[15:8] (default 0x00)
Each bit selects 4X or 16X sampling rate for that UART channel. The
4XMODE 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, bit [0] is channel 0 and can only be controlled by
channel 0. All other bits are read-only in channel 0. Logic 0 (default) selects
normal 16X sampling (with 8XMODE = 0x00) and logic one selects 4X
sampling rate. Transmit and receive data rates will quadruple by selecting
4X. If using the 8XMODE, the corresponding bit in this register should be
logic 0.
3.2.5 RESET[23:16] (default 0x00)
The 8-bit RESET register provides the software with the ability to reset the
UART(s) when there is a need. The RESET 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
RESET register in channel 0 will only reset channel 0. Each bit is self-clearing
after it is written a logic 1 to perform a reset to that channel. All registers in
that channel will be reset to the default condition.