Intel 4040 (i4040) microprocessor family

Intel 4040 (i4040) is an enhanced version of Intel 4004 microprocessor. The 4040 runs at the same frequency as the 4004 CPU and has the same effective speed of instruction execution - 92,000 instructions per second for single-word instructions. The 4040 CPU includes a number of improvements:

• Maximum program memory size was increased from 4 KB to 8 KB.
• Stack size of the 4040 CPU was increased to 7 levels.
• Extra bank of eight 4-bit registers was added to the CPU.
• The CPU is capable of handling interrupts.
• i4040 instruction set includes 14 new instructions - halt, logical, interrupt handling and bank selection instructions.

Please see differences between Intel 4040 and 4004 microprocessors for detailed list of new features.

The Intel 4040 CPU is a part of MCS-40 chipset, which, in addition to the 4040 processor itself, includes 4001 ROM and I/O device, 4002 RAM and I/O device, 4003 shift register, 4008/4009 standard memory and I/O interface set, 4101 static RAM, 4201 clock generator, 4289 standard memory interface, 4308 ROM and I/O device, 4316 ROM, and 4702 erasable PROM.

Intel 4040 was used in Intellec 4/40 microcomputer development system and in embedded applications.

According to Intel's 4040 datasheet some microprocessors could operate in industrial temperature range, but it's not clear how these parts were marked. There are no known second-source manufacturers of Intel 4040 microprocessor.