Instruction manual

11
CPU Power Up and Initialization
This chapter covers the following topics:
• Processor initialization (Section 11.1)
• Bcache initialization (Section 11.2)
11.1 Processor initialization
Figure 14 shows the initialization process.
Figure 14 Processor Initialization Block Diagram
Power On
CPU, ASICs, PALs
Do Hardware Reset.
Init State A
(For Firmware)
Serial ROM Code
System ROM Code
Firmware
VMB/Operating System
Halt
Init State B
(For Operating System)
MR−0109−93RAGS
Initialization may be divided into the following:
• The state of the processor after power on reset and before execution of the
Serial ROM (SROM) code (Init State A) (Section 11.1.1)
• The state of the processor after the SROM code has completed execution (Init
State B).
Loading the SROM takes 64K * 200 ns for the DECchip 21064. By the time
SROM is loaded, all hardware initialization has completed.
CPU Power Up and Initialization 11–1