
Agere Systems Inc.
197
Data Sheet
July 2001
T8302 Internet Protocol Telephone
Advanced RISC Machine (
ARM
)
14 IrDA_ACC and UART_ACC
(continued)
Table 180. ACC Interrupt Enable Register
(continued)
14.3 IrDA Formatter
The IrDA formatter is only supported in the IrDA_ACC. The UART_ACC does not have this feature. It works with
the ACC to provide compatibility with the IrDA infrared serial data link standard. Features for the IrDA formatter fol-
low:
I
Operates at speeds of up to 115.2 kbits/s.
I
Programmable pulse width to the IrDA transceiver.
14.3.1 IrDA Formatter Operation
The IrDA formatter is enabled before it is used by setting
IDE
of the
IrDA feature register
(see Table 178 on page
194)
.
Figure 23
shows how the output of the IrDA formatter follows the output of the IrDA_ACC channel. When the
IrDA_ACC output is 0, the IrDA outputs a pulse high. When the IrDA_ACC output is 1, there is no pulse during that
bit time. The width of the pulse is determined by the value programmed into the
IrDA feature register
using the fol-
lowing formula:
IrDA Pulse-Width = 8 x [Clock Period x (PWC + 1)]
The
IrDA feature register
(see Table 178 on page 194)
is set to ensure that the pulse-width meets the minimum
required by the transceiver being used.
Bit #
3
Name
RXFEI
Description
Received data framing error interrupt enable.
If 1, the received data framing error interrupt is enabled.
If 0, no received framing error interrupt will be generated.
Received data overrun error interrupt enable.
2
RXOE
If 1, the received data overrun error interrupt is enabled.
If 0, no received overrun error interrupt will be generated.
Receiver FIFO half-full interrupt enable.
1
RXFHI
If 1, the receiver FIFO half-full interrupt is enabled.
If 0, no Receiver FIFO half-full interrupt will be generated.
Receiver FIFO full interrupt enable.
0
RXFFI
If 1, the receiver FIFO full interrupt is enabled.
If 0, no receiver FIFO full interrupt will be generated.