Interface to Recommended

I/O Chips
4 Mb/s Ir link distances of 1.3-1.95
meters between transmitter and
receiver have been demonstrated
using typical HSDL-1100 units, and
either the National Semiconductor
PC87108 I/O chip, the VLSI
VL82C147 I/O chip, or the SMC
FDC37C957 I/O chip. In reference
to the HSDL-1100 diagram on page
1 of this note, the TXD, RXD-A, and
RXD-B nodes can be connected
directly to the chosen I/O chip.
National Semiconductor
PC87108
For the National Semiconductor
PC87108 I/O chip, the Ir link can be
realized with the following connections:
Connect IRTX pin 39 of the
PC87108 to the I/O side of R1/CX2
labeled TXD on the diagram of
page 1.
Connect IRRX1 pin 38 of the
PC87108 to RXD-A (pin 8 of the
HSDL-1100).
Connect IRSLO/IRRX2 pin 37 of
the PC87108 to RXD-B (pin 5 of the
HSDL-1100).
5
For Sharp ASK/DASK using the NS
PC87108, the PC87108 should be
configured by the ASK/DASK
software to:
1. Receive data from only one
receive pin
2. Set the receive to the AUX input
IRRX2