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The TLCS-12 was a 12-bit microprocessor and central processing unit manufactured by Toshiba. It began development in 1971, and was completed in 1973. It was a 32 mm² MOS integrated circuit chip with about 2,800 silicon gates, fabricated on a 6 µm process with NMOS logic. It was used in the Ford EEC engine control unit system, which began production in 1974 and went into mass production in 1975. The system memory included 512-bit RAM, 2 kb ROM and 2 kb EPROM.
The microcontrollers in the TLCS-47 category are 4-bit systems. These are no longer advertised on the Toshiba website.
The microcontrollers in the TLCS-900 family are 16-bit (TLCS-900, TLCS-900/L, TLCS-900/H and TLCS-900/L1 series) and 32-bit (TLCS-900/H1 series) systems. Most of them are CISC based, with a few systems being RISC based.
Features and differences
Current TLCS processors offer some or all of the following features:
- multifunction, bi-directional general purpose I/O ports with optional built-in pull-up resistors
- mask programmable, one time programmable, flash memory or EEPROM type of ROM. ROMless versions are also available
- a variety of serial interfaces:
- watchdog timer (WDT)
- multiplexed 10-bit A/D converters; D/A converters
- dual clock inputs and on-line clock switching by selecting different gear values (frequency divider), thus allowing either low-power low-frequency modes or high-performance high-frequency modes
- prescalable 8-bit and 16-bit timers (may be used as Programmable Interval Timers)
- 8-bit and 16-bit pulse-width modulation (PWM) and programmable pulse generation (PPG) output
- power voltage supply range between 1.8 and 5.5 Volt
- external interrupt control
- pattern generator, suitable for stepper motor control
- Chip select/wait controller
- different chip carrier formats
As demand for these features differs widely depending on the requirements for a specific project (low energy consumption; high number of I/O ports; etc.), customers can choose from a wide range of different versions.
The free Small Device C Compiler supports the TLCS-90.
There is a project for porting GNU assembler to the TLCS-900 family.
Alfred Arnold's The Macroassembler AS  is a free assembler supporting the TLCS-47, TLCS-870, TLCS-90, TLCS-900 and TLCS-9000 families.
- "1973: 12-bit engine-control microprocessor (Toshiba)" (PDF). Semiconductor History Museum of Japan. Retrieved 27 June 2019.
- Belzer, Jack; Holzman, Albert G.; Kent, Allen (1978). Encyclopedia of Computer Science and Technology: Volume 10 - Linear and Matrix Algebra to Microorganisms: Computer-Assisted Identification. CRC Press. p. 402. ISBN 9780824722609.