Motorola MPC8260 - Manual (Page 77)

MOTOROLA Chapter 1. Overview 1-7
Part I. Overview
The following list summarizes the major features of the CPM:
¥ The CP is an embedded 32-bit RISC controller residing on a separate bus (CPM
local bus) from the 60x bus (used by the system core). With this separate bus, the CP
does not affect the performance of the PowerPC core. The CP handles the lower
layer tasks and DMA control activities, leaving the PowerPC core free to handle
higher layer activities. The CP has an instruction set optimized for communications,
but can also be used for general-purpose applications, relieving the system core of
small often repeated tasks.
¥ Two serial DMA (SDMA) that can do simultaneous transfers, optimized for burst
transfers to the 60x bus and to the local bus.
¥ Three full-duplex, serial fast communications controllers (FCCs) supporting ATM
(155 Mbps) protocol through UTOPIA2 interface (there are two UTOPIA interfaces
on the MPC8260), IEEE 802.3 and Fast Ethernet protocols, HDLC up to E3 rates
(45 Mbps) and totally transparent operation. Each FCC can be conÞgured to transmit
fully transparent and receive HDLC or vice-versa.
¥ Two multichannel controllers (MCCs) that can handle an aggregate of 256 X 64
Kbps HDLC or transparent channels, multiplexed on up to eight TDM interfaces.
The MCC also supports super-channels of rates higher than 64 Kbps and
subchanneling of the 64-Kbps channels.
¥ Four full-duplex serial communications controllers (SCCs) supporting IEEE802.3/
Ethernet, high- level synchronous data link control, HDLC, local talk, UART,
synchronous UART, BISYNC, and transparent.
¥ Two full-duplex serial management controllers (SMC) supporting GCI, UART, and
transparent operations
¥ Serial peripheral interface (SPI) and I
2
C bus controllers
¥ Time-slot assigner (TSA) that supports multiplexing of data from any of the four
SCCs, three FCCs, and two SMCs.
1.3 Software Compatibility Issues
As much as possible, the MPC8260 CPM features were made similar to those of the
previous devices (MPC860). The code ßow ports easily from previous devices to the
MPC8260, except for new protocols supported by the MPC8260.
Although many registers are new, most registers retain the old status and event bits, so an
understanding of the programming models of the MC68360, MPC860, or MPC85015 is
helpful. Note that the MPC8260 initialization code requires changes from the MPC860
initialization code (Motorola provides reference code).
1.3.1 Signals
Figure 1-2 shows MPC8260 signals grouped by function. Note that many of these signals
are multiplexed and this Þgure does not indicate how these signals are multiplexed.