Embedded Solutions
Page 22 of 50
BIS3_IO_UCNTL
[$20] BiSerial III Upper Control Port read/write
Upper Bits Control Port
DATA BIT
DESCRIPTION
25-24
Mux 33,32
17-16
Termination 33,32
9-8
Direction 33,32
1-0 Data
32,32
FIGURE 15
PMC BISERIAL-III UPPER CONTROL PORT
The BiSerial III has 34 transceivers. The upper control bits are concentrated within this
register to cover the top 2 bits not controlled within the other control registers. The
upper bits are only useable on the Bezel I/O connector. Pn4 has only 64 connections
and doesn’t support the upper lines. The definitions are the same as the Data, Term,
Dir and Mux port definitions for bit operation.
Data = Data transmitted when the Mux is set to ‘0’ and the direction is set to ‘1’.
Termination when set to ‘1’ causes the parallel termination to be engaged. Setting the
Mux control bits to ‘0’ creates a parallel port for those bits. Setting the Mux control bits
to ‘1’ enables the state-machine to control the direction and data lines. The termination
control is independent.
BIS3_IO_RDBK
[$C0] BiSerial III I/O Read-Back Port read only
I/O Read-Back Port
DATA BIT
DESCRIPTION
31-0
I/O Data 31-0
FIGURE 16
PMC BISERIAL-III I/O READBACK PORT
The I/O lines can be read at any time. The value is not filtered in any way. If the
transceivers are set to TX by the parallel port or state-machine then the read-back
value will be the transmitted value. If the transceivers are set to receive then the port
values will be those received by the transceivers from the external I/O.
