User`s guide

KA52/53/54 CPU Module Description

This chapter describes the KA52 central processing unit (CPU) module

that is used in the VAX 4000 Model 100 and 100A systems, the KA53 CPU

module that is used in the VAX 4000 Model 105A systems and the KA54 CPU

module that is used in the VAX 4000 Model 106A. It gives information on the

following:

• KA52/53/54 CPU modules

• MS44 or MS44L memory modules

The KA52, KA53, and KA54 are similar in design, and the information in this

document is applicable to either except where noted. The differences between

the KA52, KA53, and KA54 CPUs are as follows:

KA52 KA53 KA54

Speed 71Mhz (14ns) 83Mhz (12ns) 400 Mhz (10ns)

Cache 128Kb 512Kb 512Kb

1.1 KA52/53/54 CPU Module

The KA52/53/54 CPU module is based on the NVAX chip set. It uses MS44

or MS44L memory modules, a set of supported small computer system

interface (SCSI) devices, and a DSSI bus interface through which the

processor can communicate with DSSI mass storage devices. Figure 1–1 shows

the KA52 CPU module; the KA53 and KA54 modules are similar.

KA52/53/54 CPU Module Description 1–1