Motorola PowerQUICC II MPC8280 Series Reference Manual page 967

29.3.4.4.4 Resetting the SU Filtering Mechanism
This command resets the filtering algorithm to ensure that the next SU will be received,
even if it would normally have been filtered. This command could be issued periodically
so that the 603e core can check to make sure that the link is really up and not simply
receiving flags.
To issue this MCC command, refer to Section 14.4, "Command Set." Use opcode 1110
(0xE).
29.3.4.5 Octet Counting Mode—SS7 Mode
When entering the octet counting mode (OCM), the CP will load the user defined N register
to its internal octet counter. While in the octet counting mode the CP will decrement its
internal counter for every unstuffed octet received. When the internal counter is
decremented to zero, the CP increment the SUERM register and reload the N register into
the internal count register. In addition an interrupt (OCT) might be generated depending on
the interrupt mask. The SS7 controller will enter octet counting mode under the following
circumstances:
• An ABORT character is received at any time and SS7_OPT[O_ITUT] is set.
• The SU currently being received has exceeded the length programmed in the MFLR
register and SS7_OPT[O_ITUT] is set.
• The receiver overruns and SS7_OPT[O_ORN] is set. Note that when no receive
buffers are available, only octets are counted; that is, D_cnt is not decremented after
receiving the frame.
The SS7 controller will leave octet counting mode when a valid signal unit is detected (with
a valid CRC and a length less than MFLR and greater than 4).
Octet counting mode applies only to the ITU-T and ANSI
standards. The SS7 microcode will not work if both the
Japanese standard and OCM features are selected.
29.4 Channel Extra Parameters
In addition to the information kept in the channel-specific parameter ram, a channel also
has a set of pointers used to index its transmit and receive buffer descriptors. This
information is kept in a set of channel-extra parameters. Table 29-14 describes the
channel-extra parameters. These parameters are indexed using the channel number, as
described in the table.
MOTOROLA
Freescale Semiconductor, Inc.
NOTE
Chapter 29. Multi-Channel Controllers (MCCs)
For More Information On This Product,
Go to: www.freescale.com
Channel Extra Parameters
29-29