AN2798 Freescale Semiconductor / Motorola, AN2798 Datasheet - Page 3

• Manufacturer Part Number: AN2798
• Description: Migrating from the MPC855T to the MPC885
• Manufacturer: Freescale Semiconductor / Motorola

3 The MPC885
The MPC885 PowerQUICC™ is a 0.18 µm version of the MPC860 PowerQUICC family of communications
microprocessors. Unlike the MPC855T, the MPC885 has a core voltage of 1.8 V and an I/O voltage of 3.3 V, with
5V-input compatibility (on some I/O pins). The MPC885 supports a maximum core speed of 133 MHz and a
maximum external bus speed of 80 MHz (in 1:1 mode).
The MPC885 incorporates the same embedded MPC8XX processor core and similar CPM and SIU. The MPC885
also supports an on-chip security engine and two 10/100 Fast Ethernet controller modules. The CPM supports
USB 1.1, three SCCs (SCC2, SCC3, and SCC4), two SMCs (SMC1 and SMC2), SPI, and I
support 802.3 Ethernet, ATM, HDLC/SDLC, UART and transparent protocols.
Figure 1
Freescale Semiconductor
shows the MPC885 block diagram.
Embedded
Processor
MPC8xx
Fast Ethernet
Media Access
Core
Controller
MIII / RMII
Base-T
Control
10/100
DMAs
FIFOs
DMAs
Load/Store
Instruction
Bus
Bus
Parallel Interface Port
Migrating from the MPC855T to the MPC885, Rev. 0
Instruction Cache
Instruction MMU
32-Entry DTLB
32-Entry ITLB
Data Cache
4 Baud Rate
Data MMU
Parallel I/O
Generators
USB
8-Kbyte
8-Kbyte
Figure 1. MPC885 Block Diagram
SCC2
Timers
Timers
4
Slave / Master IF
SCC3
Time-Slot Assigner
32-Bit RISC Controller
Controllers
Interrupt
and Program
Unified
UTOPIA
SCC4/
Bus
ROM
Serial Interface
Serial Interface
Dual-Port RAM
SMC1
8-Kbyte
Security Engine
Controller
Channel
System Interface Unit (SIU)
Bus Interface
Internal
SMC2
PCMCIA-ATA Interface
Unit
Memory Controller
System Functions
AESU
Bus Interface
SPI
Virtual IDMA
Serial DMAs
External
Unit
2
DEU
and
C. The SCCs can
I
2
C
MDEU
The MPC885
3