W90221X Winbond Electronics Corp America, W90221X Datasheet - Page 160

• Manufacturer Part Number: W90221X
• Description: Pa-risc Embedded Controller
• Manufacturer: Winbond Electronics Corp America

Bit 0-7 Low byte of baud rate dvisor
Divisor Latch (high byte) Register (DLM)
Port address : 0xf00003f9, DLAB=1 (COM0)
Default : 0x0
Bit 0-7 High byte of baud rate dvisor
The 16-bit Divisor ({DLM, DLL}) is used to determine the COM port's baud
rate. The equation
is
Interrupt Identification Register (IIR)
Port address : 0xf00003fa (COM0)
Default : ---
Bits 0 Status of "FIFO Mode Enable"
always enable,
Bit 1-2 Status of RX FIFO threshold level
The meaning of
W90221X version 0.6
FMENo
0
0
This bit echos if "FIFO mode" is enable or not. Since "FIFO mode" is
this bit always shows logical 1 when CPU reading this register.
These bits show current setting of receiver FIFO threshold level (RTH).
RTH is defined in the following FCR description.
0xf00002f9, DLAB=1 (COM1)
0xf00002fa (COM1)
1
1
RTHo[0:1]
Baud Rate = Frequency input / {16 * [Divisor +2]}
Baud Rate Divisor (High Byte)
Baud Rate Divisor (Low Byte)
2
2
DMOD
3
3
4
4
IID[0:2]
Read/write
Read only
5
5
6
6
Power-on
Power-on
NOI
7
7
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