Specifications

B–20 I/O Space Address Maps
Subject to Change – 17 January 1997
21164 Microprocessor Cbox IPR Space
B.7 21164 Microprocessor Cbox IPR Space
The 21164 microprocessor cache control and bus interface unit (Cbox) IPR space
occupies physical addresses FF.FFF0.0000 through FF.FFFF.FFFF.
Table B–14 lists three key 21164 registers that configure the internal L2 secondary
cache (Scache) and external L3 backup cache (Bcache). For additional information,
refer to the Digital Semiconductor 21164 Alpha Microprocessor Hardware
Reference Manual.
Table B–14 21164 Cache Configuration Registers
Register Type Address Description
SC_CTL RW FF.FFF0.00A8 Scache control register
BC_CONTROL W FF.FFF0.0128 Bcache, system interface, and Bcache test
control register
BC_CONFIG W FF.FFF0.01C8 Bcache configuration register (size and
timing)