CHAPTER 1 INTRODUCTION
26 Preliminary Users Manual S15543EJ1V0UM
1.5 Block Diagram (Detail)
1.5.1 VR4120A RISC processor core
We will support real-time OS running on high performance RISC processor VR4120A core and can perform network
protocols (TCP/IP, PPP, SNMP, HTTP etc) to realize ADSL router and modem. Middleware including RTOS will be
loaded to SDRAM from external PROM and Flash ROM and by setting write protected area for such an area, high
speed processing will be realized together with large size instruction cache.
Features of VR4120A RISC Processor Core are as follows;
MIPS/I/II/III instruction set will be supported (FPU, LL, LLD, SC, SCD instruction will be excluded)
Realize high speed processing of application by supporting high speed multiply and accumulate function
Includes large size cache memory (Instruction: 16 Kbytes, Data: 8 Kbytes)
Supports up to 1T byte virtual address space by using full associative TLB
Implements switching function between Big-Endian and Little-Endian
Figure 1-3. Block Diagram of VR4120A RISC Processor
VR4120A RISC Processor Core
VR4120A Data Path
Instruction
Cache
(16 KBytes)
Data
Cache
(8 KBytes)
BUS Controller
SysAD Bus