Freescale Semiconductor MPC8260 - Manual (Page 567)

Communications Processor Module Overview
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 14-19
Figure 14-8. Dual-Port RAM Memory Map
The dual-port RAM data bus is 64-bits wide. The RAM is used for the following tasks:
• To store parameters associated with the FCCs, SCCs, MCCs, SMCs, SPI, I 2 C, and IDMAs in the
parameter RAM.
• To store buffer descriptors (BDs).
• To hold data buffers (optional because data can also be stored in external memory).
• For temporary storage of FCC data moving to/from an FCC FIFO (using the BTM) from/to
external memory (using SDMA).
• To store RAM microcode for the CP. This feature allows Freescale to add protocols in the future.
• For additional scratch-pad RAM space for user software.
The RAM is designed to serve multiple requests at the same cycle, as long as they are not in the same bank.
Only the parameters in the parameter RAM and the microcode RAM option require fixed addresses to be
used. The BDs, buffer data, and scratchpad RAM can be located in the dual-port system RAM or in any
BD/Data/µCode
2 KBytes
Bank #1
0x0000
BD/Data/µCode
2 KBytes
Bank #2
0x0800
BD/Data/µCode
2 KBytes
Bank #3
0x1000
BD/Data/µCode
2 KBytes
Bank #4
0x1800
BD/Data/µCode
2 KBytes
Bank #5
0x2000
BD/Data/µCode
2 KBytes
Bank #6
0x2800
BD/Data
2 KBytes
Bank #7
0x3000
BD/Data
2 KBytes
Bank #8
0x3800
Parameter RAM
2 KBytes
Bank #9
0x8000
Parameter RAM
2 KBytes
Bank #10
0x8800
BD/Data/µCode
2 KBytes
Bank #11
0x9000
BD/Data/µCode
2 KBytes
Bank #1
BD/Data/µCode
2 KBytes
Bank #1
BD/Data/µCode
2 KBytes
Bank #1
FCC Data
2 KBytes
Bank #11
0xB000
FCC Data
2 KBytes
Bank #12
0xB800
Reserved
(Partially Reserved)
Microcode
2 KBytes
1
Bank #13
0x4000
Microcode
2 KBytes 1
Bank #14
0x4800
Microcode
2 KBytes
1
Bank #15
0x5000
Microcode
2 KBytes
1
Bank #16
0x5800
0x6000
Reserved
1
Reserved on .29 µm (HiP3) devices.