Hi,
I am working with the Intel DB-PXA250 (lubbock/x-scale) development board
running QNX 6.1 and am trying to communicate though the serial port (either
BTUART or FFUART) with out any flow control. For testing purposes I have
the serial port directly connected to a protocol analyzer to watch the data
xfers. The problem that I am finding is that the serial port will not
transmit any data without a space CTS signal; even with flow control
disabled.
I have the serial driver loaded as follows:
// FFUART 0x4010 0000, 22
// BTUART 0x4020 0000, 21
// -E: Start in raw mode (the default). Software flow control is disabled by
default.
// -F: Disable hardware flow control (default to hardware flow control
enabled).
devc-serpxa250 -E -F 0x40100000,22 0x40200000,21
In the test code I open up the fd to dev/ser2 (using BTUART for this
example), and forever write 0x55 out to the port. With software/hardware
flow control disabled and CTS inactive (mark), nothing is transfered.
However once I supply an active CTS (space), data transfer successfully
occurs.
My application only uses RX/TX for serial communication; no flow control is
used at all. Are there any steps that I am overlooking to get serial
communication without flow control?
Thanks
-nick
I have verified that on an x86 (intel pentium 3), that the same code works
as expected under QNX; with hardware/software flow control disabled, CTS is
a dont care. However on the Lubbock, CTS is still required.
“Nick Cianfrocco” <ncianfro@harris.com> wrote in message
news:ak5kna$pl2$1@inn.qnx.com…
Hi,
I am working with the Intel DB-PXA250 (lubbock/x-scale) development board
running QNX 6.1 and am trying to communicate though the serial port
(either
BTUART or FFUART) with out any flow control. For testing purposes I have
the serial port directly connected to a protocol analyzer to watch the
data
xfers. The problem that I am finding is that the serial port will not
transmit any data without a space CTS signal; even with flow control
disabled.
I have the serial driver loaded as follows:
// FFUART 0x4010 0000, 22
// BTUART 0x4020 0000, 21
// -E: Start in raw mode (the default). Software flow control is disabled
by
default.
// -F: Disable hardware flow control (default to hardware flow control
enabled).
devc-serpxa250 -E -F 0x40100000,22 0x40200000,21
In the test code I open up the fd to dev/ser2 (using BTUART for this
example), and forever write 0x55 out to the port. With software/hardware
flow control disabled and CTS inactive (mark), nothing is transfered.
However once I supply an active CTS (space), data transfer successfully
occurs.
My application only uses RX/TX for serial communication; no flow control
is
used at all. Are there any steps that I am overlooking to get serial
communication without flow control?
Thanks
-nick
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