ST18-AU1 STMICROELECTRONICS [STMicroelectronics], ST18-AU1 Datasheet - Page 46

• Manufacturer Part Number: ST18-AU1
• Description: SIX-CHANNEL DOLBY AC3/MPEG2 AUDIO DECODER
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST18-AU1
11 MEMORY
11.1 Internal memory resource
One 8 Kword and two 16 Kword single port memories are included on-chip:
Note: the first 256 addresses of the Y space are reserved for the D950 memory-mapped
registers and for on-chip memory mapped peripherals.
Memory can be extended off-chip in one of two ways:
The specific details on the operation of the BSU are described separately in Chapter 12.
Figure 11.1
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FFFF
3FFF
0000
All addresses are hexadecimal
External memory is accessed directly or through the bus switch
Internal RAM
1: directly for I and X memory spaces
2: through the bus switch unit for all three memory spaces
X-memory
External
Instruction memory on I space from address 0 to 16382 (16 K)
X-Data memory on X space from address 0 to 16382 (16 K)
Y-Data memory on Y space from address 256 to 8192
Memory mapping
64k
16k
FFFF
00FF
1FFF
Internal RAM
Y-memory
Registers
External
8k
64k
FFFF
3FFF
0000
Internal RAM
I-memory
External
16k
64k