MPC555
/
MPC556
UNIFIED SYSTEM INTERFACE UNIT
MOTOROLA
USER’S MANUAL
Rev. 15 October 2000
5-6
shows the PowerPC special address range. For an external master access-
ing a PowerPC SPR, address bits [0:17] and [28:31] are compared to zeros to confirm
that an SPR access is valid.
Table 5-2 USIU Special-Purpose Registers
Internal
Address[0:31]
Register
Decimal Address
spr[5:9]:spr[0:4]
1
NOTES:
1. Bits [0:17] and [28:31] are all 0.
0x2C00
Decrementer (DEC)
22
0x1880
Time Base — Read (TB)
268
0x1A80
Time Base Upper — Read (TBU)
269
0x3880
Time Base — Write (TB)
284
0x3A80
Time Base Upper — Write (TBU)
285
0x3B30
Internal Memory Mapping Register (IMMR)
638
Table 5-3 PowerPC Address Range
0:17
18:27
28:31
0 . . . 0
spr[0:9]
0000
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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