AMD 29050

The Am29050 is a RISC microprocessor manufactured by AMD Systems. It is a high-performance, general-purpose, 32-bit microprocessor utilising CMOS technology. The marking 40GI on the chip indicates that this is a 40 MHz processor available in the following speeds. The letter "I" indicates "Industrial grade", whereas a C would indicate "Commercial grade", and the industrial grade is for critical applications such as avionics.

• 20 MHz
• 25 MHz
• 33 MHz
• 40 MHz

Pin Grid Array (PGA)

This is a 169-lead pin grid array (PGA) package. The PGA has 141 signal pins, 27 power and ground pins, and one alignment pin. The letter G indicates that the package type is 169 pins PGA.

Triple Bus Architecture

The Instruction Bus transfers instructions into the processor, the Data Bus transfers data to and from the processor, and the Address Bus provides addresses for both instructions and data accesses. The address bus also doubles its functionality for transferring data to a co-processor. Since both the address and data buses transfer data, the Am29050 microprocessor can transfer 64-bits of information to the co-processor in one cycle.

A floating-point unit (FPU) provides single-precision and double-precision floating-point operations. There is independent divide and square root circuitry, which enables these functions to proceed in parallel with other operations. By assigning a special address space on the bus channel, a co-processor can attach directly to the processor. This permits the transfer of operands and other information on the address bus without interfering with normal addressing functions. The 29000 family of microprocessors have three-address instruction set architecture, and the programmer has complete freedom to allocate register usage. There are 192 general-purpose registers, allowing the retention of intermediate calculations thereby avoiding the unnecessary destruction of data.

There are 125 instructions in the set, which divide into nine classes. These are integer arithmetic, compare, logical, shift, data movement, constant, floating point, branch, and miscellaneous. All instructions can complete within a single processor cycle.

Versions

Some compatible processors within the 2900 family range. All of the processors within the AMD 2900 range have three-bus architecture.

Specifications

• Full 32 bit, three-bus architecture
• 55 million instructions per second (MIPS)
• On-chip double-precision floating-point arithmetic unit
• CMOS technology that is TTL compatible
• 4 GB virtual address space with demand paging