Intel PXA255 Personal Computer User Manual


 
Intel® PXA255 Processor Developer’s Manual 11-13
Fast Infrared Communication Port
11.3.5 FICP Status Register 0 (ICSR0)
The ICSR0, shown in Table 11-6, contains bits that signal the transmit FIFO service request,
receive FIFO service request, receiver abort, transmit FIFO underrun, framing error, and the end/
error in receive FIFO conditions. Each of these hardware-detected events signal an interrupt
request to the interrupt controller.
If a bit signals an interrupt request, it signals the interrupt request as long as the bit is set. When the
bit is cleared, the interrupt is cleared. Read/write bits are called status bits. Read-only bits are
called flags. Status bits that must be cleared by software after they are set by hardware are called
sticky status bits. Writing a 1 to a sticky status bit clears it. Writing a 0 to a sticky status bit has no
effect. Read-only flags are set and cleared by hardware. Writes to read-only flags have no effect.
Some bits that cause interrupts have corresponding mask bits in the control registers.
This is a read/write register. Ignore reads from reserved bits. Write zeros to reserved bits.
.
Table 11-6. ICSR0 Bit Definitions (Sheet 1 of 2)
0x4080_0014
Fast Infrared Communication Port
Status Register 0 (ICSR0)
Fast Infrared Communication Port
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
reserved
FRE
RFS
TFS
RAB
TUR
EIF
Reset 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
Bits Name Description
[31:6] reserved
5FRE
Framing error.
0 = No framing errors encountered in the receipt of this data.
1 = Framing error occurred. A preamble was followed by something other than another
preamble or start flag, request interrupt.
4RFS
Receive FIFO service request (read-only).
0 = Receive FIFO has not reached it trigger level or receiver disabled.
1 = Receive FIFO has reached its trigger level and receiver is enabled. DMA service
request signalled. Interrupt request signalled if not masked by ICCR0[RIE].
3TFS
Transmit FIFO service request (read-only).
0 = Transmit FIFO has more than 96 entries of data or transmitter disabled.
1 = Transmit FIFO has 96 or less entries of data and transmitter is enabled. DMA service
request signalled. Interrupt request signalled if not masked by ICCR0[TIE].