Jameco Electronics Rabbit 2000 Manual Do Utilizador
User’s Manual
175
Table 12-16. Serial Port Control Register Ports E and F
Serial Port x Control Register
(SECR)
(Address = 0xCC)
(SFCR)
(Address = 0xDC)
Bit(s)
Value
Description
7:6
00
No operation. These bits are ignored in the Async mode.
01
In HDLC mode, force receiver in Flag Search mode.
10
No operation.
11
In HDLC mode, transmit an Abort pattern.
5
0
Enable the receiver input.
1
Disable the receiver input.
4
x
This bit is ignored.
3:2
00
Async mode with 8 bits per character.
01
Async mode with 7 bits per character. In this mode the most significant bit of a
byte is ignored for transmit, and is always zero in receive data.
byte is ignored for transmit, and is always zero in receive data.
10
HDLC mode with external clock. The external clocks are supplied as follows:
•
Transmit clock (Serial Port F)—pins PG0 and PG1on Parallel Port G.
•
Receive clock (Serial Port E)—pins PG4 and PG5 on Parallel Port G.
11
HDLC mode with internal clock. The clock is 16× the data rate, and the DPLL is
used to recover the receive clock. If necessary, the clocks are supplied as follows:
used to recover the receive clock. If necessary, the clocks are supplied as follows:
•
Transmit clock (Serial Port F)—pins PG0 and PG1on Parallel Port G.
•
Receive clock (Serial Port E)—pins PG4 and PG5 on Parallel Port G.
1:0
00
The serial port interrupt is disabled.
01
The serial port uses Interrupt Priority 1.
10
The serial port uses Interrupt Priority 2.
11
The serial port uses Interrupt Priority 3.