Ftxl transceiver interface, Reset signal – Echelon FTXL Hardware User Manual
Page 73
FTXL Hardware Guide
65
The FtxlHal.c file defines the following functions to handle interrupts:
• LonRegisterIsr()
Initializes the interrupt system, including registering the interrupt
handlers described in
on page 64.
• LonEnableInterrupt()
Used to enable either or both of the interrupts.
• LonDisableInterrupt()
Used to disable either or both of the interrupts.
FTXL Transceiver Interface
The interface between the Nios II processor and the FTXL Smart Transceiver
includes the following signals:
• A bi-direction reset signal
• A set of status signals that are used to determine when the FTXL
Transceiver is ready to accept data or has data to be read
• A bi-directional 8-bit data register
• An interrupt
These signals cannot be tested in isolation. For example, you cannot test the
data register without first verifying that the FTXL Transceiver has been properly
reset and that the status register is properly reporting its state. And you cannot
completely test the status register without transferring some data.
on page 70 describes the series of tests, to be performed in order, that fully
test communications between the Nios II processor and the FTXL Transceiver.
The following sections describe the interface. See Chapter 3,
, on page 19, for additional information about the FTXL
transceiver interface.
Reset Signal
The interface includes a bi-direction reset signal. For most of the time, this
signal is configured as an input. The input includes an edge-capture register,
which the Nios II processor can read to determine whether the FTXL Transceiver
has been reset. The FTXL function LonReadTransceiverReset() reads the reset
capture register.
To reset the FTXL Transceiver, the host processor configures this signal as an
output, asserts the signal, then reconfigures the signal as an input to deassert
the signal. The following FTXL HAL functions configure the reset signal:
LonAssertTransceiverReset() and LonDeassertTransceiverReset(). In addition,
the LonDeassertTransceiverReset() function also clears the reset capture
register.
The LonReadTransceiverReset() function reads the reset capture register, which
is set by the FTXL Transceiver reset pin. The LonAssertTransceiverReset() and