Embedded Solutions
Page 18 of 37
BIS3_IO_RDBK
[$C0] BiSerial III I/O Read-Back Port read only
I/O Read-Back Port
DATA BIT
DESCRIPTION
31-0
I/O Data 31-0
FIGURE 11
PMC BISERIAL-III SDLC I/O READBACK PORT
The I/O lines can be read at any time. The value is not filtered in any way. If the
transceivers are set to TX by the parallel port or state-machine then the read-back
value will be the transmitted value. If the transceivers are set to receive then the port
values will be those received by the transceivers from the external I/O.
BIS3_IO_RDBKUPR
[$C4] BiSerial III I/O Upper Read-Back Port read only
I/O Upper Read-Back Port
DATA BIT
DESCRIPTION
1-0
I/O Data 33-32
FIGURE 12
PMC BISERIAL-III SDLC 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. The upper bits
are presented on this port.