W90220F Winbond Electronics Corp America, W90220F Datasheet - Page 60

• Manufacturer Part Number: W90220F
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

The above information is the exclusive intellectual property of Winbond Electroncs Corp. and shall not be dsiclosed or distributed or reproduced without permission from
Winbond.
60
Bits 0
Bit 1-2 Status of RX FIFO threshold level
Bit 3
Bit 4-6 Interrupt Identification bits
Bit 7
FMENo
0
Status of "FIFO Mode Enable"
This bit echos if "FIFO mode" is enable or not. Since "FIFO mode" is always enable,
this bit always shows logical 1 when CPU reading this register.
These bits show current setting of receiver FIFO threshold level (RTH). The meaning of
RTH is defined in the following FCR description.
DMA mode select
The DMA function is not implemented in this version. Reading IIR, the bit-3 is always 0.
The IID[0:2] along with NOI indicate current interrupt request from COM port
No Interrupt (NOI) pended
Table 5.2.5-3 : Interrupt Control Functions
IIR[4:7]
- - - 1
0xf00002fa (COM2)
0 1 1 0
0 1 0 0
1 1 0 0
0 0 1 0
1
RTHo[0:1]
Highest
Priority
Second
Second
Third
2
--
DMOD
Receiver Line
Status
(Irpt_RLS)
Received Data
Available
(Irpt_RDA)
Receiver FIFO
Time-out
(Irpt_TOUT)
Transmitter
Hoding Register
Empty
(Irpt_THRE)
3
Interrupt Type
None
4
Overrun Error or
Parity Error or
Framing Error or
Break Interrupt
Receiver FIFO thres-
hold level is reached
Receiver FIFO is non-
empty and no
activities are occured
in receiver FIFO
during the TOR
defined time duration
Transmitter Holding
Register Empty
IID[0:2]
Interrupt Source
5
None
6
Reading the LSR
Receiver FIFO drops
below the threshold
level
Reading the RBR
Reading the IIR (if
source of interrupt is
Irpt_THRE) or
writing into the THR
NOI
Interrupt Reset
7
control
--
W90220F
Version 0.84