se_hdlc(7D) Devices se_hdlc(7D)NAMEse_hdlc - on-board high-performance serial HDLC interface
SYNOPSIS
se@bus_address:port_number[, hdlc]
DESCRIPTION
The se_hdlc devices are a synchronous hdlc-framing interface for the
se serial devices. Both built-in serial ports (port_number) on plat‐
forms which have the se serial devices, support synchronous data trans‐
fer at a maximum rate of 384 kbps. bus_address is the platform specific
se device bus address. port_number is a single digit number (0-9).
APPLICATION PROGRAMMING INTERFACE
The se_hdlcn devices provide a data path which supports the transfer
of data via read(2) and write(2) system calls, as well as ioctl(2)
calls. Data path opens are exclusive in order to protect against
injection or diversion of data by another process.
The se_hdlc device provides a separate control path for use by programs
that need to configure or monitor a connection independent of any
exclusive access restrictions imposed by data path opens. Up to three
control paths may be active on a particular serial channel at any one
time. Control path accesses are restricted to ioctl(2) calls only; no
data transfer is possible.
When used in synchronous modes, the SAB 82532 ESCC supports several
options for clock sourcing and data encolding. Both the transmit and
receive clock sources can be set to be the external Transmit clock
(TRxC), external Receive Clock (RTxC), the internal Baud Rate Generator
(BRG), or the output of the ESCC 's Digital Phase-Lock Loop (DPLL).
The BRG is a programmable divisor that derives a clock frequency from
the PCLK input signal to the ESCC. The programmed baud rate is trans‐
lated into a floating point (6-bit mantissa, 4-bit exponent) number
time constant that is stored in the ESCC.
A local loopback mode is available, primarily for use by syncloop(1M)
for testing purposes, and should not be confused with SDLC loop mode,
which is not supported on this interface. Also, an auto-echo feature
may be selected that causes all incoming data to be routed to the
transmit data line, allowing the port to act as the remote end of a
digital loop. Neither of these options should be selected casually, or
left in use when not needed.
The se driver keeps running totals of various hardware generated events
for each channel. These include numbers of packets and characters sent
and received, abort conditions detected by the receiver, receive CRC
errors, transmit underruns, receive overruns, input errors and output
errors, and message block allocation failures. Input errors are logged
whenever an incoming message must be discarded, such as when an abort
or CRC error is detected, a receive overrun occurs, or when no message
block is available to store incoming data. Output errors are logged
when the data must be discarded due to underruns, CTS drops during
transmission, CTS timeouts, or excessive watchdog timeouts caused by a
cable break.
IOCTLS
The se driver supports the following ioctl() commands.
S_IOCGETMODE Return a struct scc_mode containing parameters
currently in use. These include the transmit
and receive clock sources, boolean loopback and
NRZI mode flags and the integer baud rate.
S_IOCSETMODE The argument is a struct scc_mode from which
the ESCC channel will be programmed.
S_IOCGETSTATS Return a struct sl_stats containing the current
totals of hardware-generated events.
These include numbers of packets and charac‐
ters sent and received by the driver, aborts
and CRC errors detected, transmit underruns,
and receive overruns.
S_IOCCLRSTATS Clear the hardware statistics for this channel.
S_IOCGETSPEED Returns the currently set baud rate as an inte‐
ger. This may not reflect the actual data
transfer rate if external clocks are used.
S_IOCGETMCTL Returns the current state of the CTS and DCD
incoming modem interface signals as an integer.
The following structures are used with se hdlc ioctl() commands:
struct scc_mode {
char sm_txclock; /* transmit clock sources */
char sm_rxclock; /* receive clock sources */
char sm_iflags; /* data and clock inversion flags (non-zsh) */
uchar_t sm_config; /* boolean configuration options */
int sm_baudrate; /* real baud rate */
int sm_retval; /* reason codes for ioctl failures */
};
struct sl_stats {
long ipack; /* input packets */
long opack; /* output packets */
long ichar; /* input bytes */
long ochar; /* output bytes */
long abort; /* abort received */
long crc; /* CRC error */
long cts; /* CTS timeouts */
long dcd; /* Carrier drops */
long overrun; /* receive overrun */
long underrun; /* transmit underrun */
long ierror; /* input error */
long oerror; /* output error */
long nobuffers; /* receive side memory allocation failure */
};
ERRORS
An open() will fail if a STREAMS message block cannot be allocated or
under the following conditions:
ENXIO The unit being opened does not exist.
EBUSY The device is in use by another serial protocol.
An ioctl() will fail under the following conditions:
EINVAL An attempt was made to select an invalid clocking
source.
EINVAL The baud rate specified for use with the baud rate gen‐
erator would translate to a null time constant in the
ESCC's registers.
FILES
/dev/se_hdlc[0-1], /dev/se_hdlc character-special devices
/usr/include/sys/ser_sync.h header file specifying synchronous
serial communication definitions
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
┌─────────────────────────────┬─────────────────────────────┐
│ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
├─────────────────────────────┼─────────────────────────────┤
│Architecture │SPARC │
└─────────────────────────────┴─────────────────────────────┘
SEE ALSOsyncinit(1M), syncloop(1M), syncstat(1M), ioctl(2), open(2), read(2),
write(2), attributes(5), se(7D), zsh(7D)
Siemens ESCC2 SAB 82532 Enhanced Serial Communication Controller User's
Manual
DIAGNOSTICSse_hdlc clone open failed, no memory, rq=nnn
A kernel memory allocation failed for one of the private data
structures. The value of nnn is the address of the read queue
passed to open(2).
se_hdlc: clone device must be attached before use!
An operation was attempted through a control path before that path
had been attached to a particular serial channel.
se_hdlcn: not initialized, can't send message
An M_DATA message was passed to the driver for a channel that had
not been programmed at least once since the driver was loaded. The
ESCC's registers were in an unknown state. The S_IOCSETMODE ioctl
command performs the programming operation.
sen hdlc_start: Invalid message type d on write queue
driver received an invalid message type from streams.
se_hdlcn: transmit hung
The transmitter was not successfully restarted after the watchdog
timer expired. This is usually caused by a bad or disconnected
cable.
SunOS 5.10 1 Jan 1997 se_hdlc(7D)
