Digital Equipment DEC 3000 600 AXP, Service Information

Page: 24 / 461

Components and Features
System Module
The system module (Syscard shown in Figure 1–1) consists of:
• DECchip 21064 processor chip
• DECchip 21064 Icache and Dcache
• Bcache and main memory control
• TURBOchannel interface
Interconnection: The system card (Syscard) provides
connectors to interface to the DEC 3000 Model 600/600S
AXP I/O module (SPIOMOD) and to the SIMM MMB modules.
SLICE Chips: The primary data paths on the Syscard are
contained within the SLICE chips. The SLICE chips interface
the 128-bit DECchip 21064 bus to a main memory bus that is
256 bits wide and to the I/O bus that is 32 bits wide.
ELVIS Chip: The addresses for main memory, I/O, and the
Bcache are controlled by the ELVIS chip.
I/O Module
The DEC 3000 Model 600/600S AXP I/O module (SPIOMOD,
Figure 1–2) contains all of the internal and external I/O
connectors along with three TURBOchannel options connectors.
The I/O module has the following features:
• Two SCSI-2 interface chips
• Interface to the TURBOchannel
• Ethernet, ISDN, printer, and audio communication ports that
have DMA
• 32K-entry scatter/gather map for virtual DMA
The I/O module contains the following hardware jumpers:
• ROM Update jumper–Enables/disables the writeable feature
of the FEPROMs.
• Secure System jumper–When placed in the enabled position,
this jumper enables the operator to lock out certain console
commands from unauthorized users. It can also be used to
clear a forgotten password.
1–3