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Dual-port ram memory map -16 – Motorola MPC8260 User Manual

Page 446

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13-16

MPC8260 PowerQUICC II UserÕs Manual

MOTOROLA

Part IV. Communications Processor Module

Figure 13-8. Dual-Port RAM Memory Map

The dual-port RAM data bus is 64-bits wide. The RAM is used for six possible 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 Motorola 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.

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

BD/Data/µCode

2 KBytes

Bank #1

0x4000

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

BD/Data/µCode

2 KBytes

Bank #1

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

Reserved

(Partially Reserved)