Appendix C Functional Description C-5
FIGUREC-2 UPA Address and Data Buses Functional Block Diagram
C.1.2 System Controller
The system controller ASIC, also known as Marvin, implements the central resource
for the UPAprotocol. It performs the following functions:
■Accepts UPArequest packets from the three masters; two processors and
PSYCHO+, and routes them to the correct slave destination.
■Maintains cache coherence between the merger buffer in PSYCHO+ and the
processor cache.
■Implements blocking rules that guarantee that all requests are properly ordered.
■Controls the K9+ ASIC, and so controls the flow of data throughthe system.
■Contains a memory controller that supplies address and control lines to memory.
■Receives and distributes resets to all of the UPAclients in the system.
■Contains logic for waking up the processor in EnergyStar mode.
Marvin
UPA_ADDRBUS0
UPA_ADDRBUS1
UPA_AD0
PSYCHO+
UPA
UPA
UPA_AD3
<35:0>
<28:0>
UPA_DATA0
XB9+
P Bus
I Bus
UPA_DATA3
UPA_AD2
UPA_AD3
UPA_DATA2
UPA_DATA2
ASIC ASIC
ASIC
graphics 0
graphics 1
CPU
module
CPU
module
UPA_AD1 UPA_DATA1
0
1