Freescale Semiconductor MPC8260 - Manual (Page 865)

Multi-Channel Controllers (MCCs)
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 28-17
28.3.4 Channel-Specific SS7 Parameters
Based on the HDLC protocol, the signalling system #7 (SS7) protocol is used to manage public service
networks. The SS7 protocol operates on signal units (SU), which are analogous to HDLC frames. The
physical, data link, and network layer functions of the SS7 protocol are called the message transfer part
(MTP). Implementing the MTP layer 2 (data link) functions in host software is difficult with multiple
performance issues. The PowerQUICC II SS7 microcode enables applications requiring multi-channel
SS7 processing.
The SS7 controller is implemented using the MCC hardware with microcode running on the CPM. Each
MCC implements the following layer 2 portions of the MTP:
• Signal unit (SU) retransmission
• Automatic fill-in signal unit (FISU) transmission
• Short SU filtering
• Duplicate fill-in and link-status signal unit (FISU/LSSU) filtering
• Octet counting
• Signal unit error rate monitoring
• Good frame counter and bad frame counting
• Initial alignment (supports alignment error rate monitoring)
Host software, however, is needed to handle the following higher-level functions of the MTP layer 2 not
supported by the SS7 controller:
• Link state control
8–9 — Reserved, should be cleared during initialization.
10 TS Receive time stamp. If this bit is set a 4 byte time stamp is written at the beginning of every data buffer
that the BD points to.If this bit is set the data buffer must start from an address equal to 8*N-4 (N is
any number larger than 0).
11–12 RQN Receive queue number. Specifies the receive interrupt queue number.
00 Queue number 0
01 Queue number 1
10 Queue number 2
11 Queue number 3
13 CESM Circuit emulation service mode.
0 Normal mode
1 CES mode
14 UDC User-defined cell support.
0 User-defined ATM cells are not supported.
1 User-defined ATM cells are supported.
15 UTM Underrun template mode.
0 Retransmit the last buffer.
1 Send the user-defined template.
Table 28-9. CHAMR Field Descriptions—CES Mode (continued)
Bits Name Description