The SCC68070 is a

Philips Semiconductors NXP Semiconductors N.V. (NXP) is a Dutch semiconductor designer and manufacturer with headquarters in Eindhoven, Netherlands. The company employs approximately 31,000 people in more than 30 countries. NXP reported revenue of $11.06 billion in 2 ...

-branded,

Motorola 68000 The Motorola 68000 (sometimes shortened to Motorola 68k or m68k and usually pronounced "sixty-eight-thousand") is a 16/32-bit complex instruction set computer (CISC) microprocessor, introduced in 1979 by Motorola Semiconductor Products Sector ...

-based 16/32-bit processor produced under license. While marketed externally as a high-performance

microcontroller A microcontroller (MCU for ''microcontroller unit'', often also MC, UC, or μC) is a small computer on a single VLSI integrated circuit (IC) chip. A microcontroller contains one or more CPUs (processor cores) along with memory and programmable i ...

, it has been almost exclusively used combined with the Philips SCC66470 VSC (Video- and Systems Controller) in the Philips CD-i interactive entertainment product line. Additions to the

core include: * Operation from 4 - 17.5 MHz * Inclusion of a minimal, segmented MMU supporting up to 16 MB of memory * Built-in DMA controller *

I²C I2C (Inter-Integrated Circuit, ), alternatively known as I2C or IIC, is a synchronous, multi-controller/multi-target (master/slave), packet switched, single-ended, serial communication bus invented in 1982 by Philips Semiconductors. It is wide ...

bus controller * UART * 16-bit counter/

timer A timer is a specialized type of clock used for measuring specific time intervals. Timers can be categorized into two main types. The word "timer" is usually reserved for devices that counts down from a specified time interval, while devices th ...

unit * 2 match/count/

capture Capture may refer to: *Asteroid capture, a phenomenon in which an asteroid enters a stable orbit around another body *Capture, a software for lighting design, documentation and visualisation *"Capture" a song by Simon Townshend *Capture (band), an ...

registers allowing the implementation of a pulse generator, event counter or reference timer * Clock generator Differences from the

core include these: * Instruction execution timing is completely different * Interrupt handling has been simplified * The SCC68070 has MC68010 style bus-error recovery. They are not compatible, so exception error processing is different. * The SCC68070 lacks a dedicated

address generation unit The address generation unit (AGU), sometimes also called address computation unit (ACU), is an execution unit inside central processing units (CPUs) that calculates addresses used by the CPU to access main memory. By having address calculation ...

(AGU), so operations requiring address calculation run slower due to contention with the shared ALU. This means that most instructions take more cycles to execute, for some instructions significantly more, than a 68000. * The MMU is not compatible with the

Motorola 68451 The MC68451 is a Motorola (now Freescale) Memory Management Unit (MMU), which was primarily used in conjunction with the Motorola MC68010 microprocessor. The MC68451 supported a 16 MB address space and provided a MC68000 or a MC68010 with sup ...

or any other "standard"

Motorola Motorola, Inc. () was an American Multinational corporation, multinational telecommunications company based in Schaumburg, Illinois, United States. After having lost $4.3 billion from 2007 to 2009, the company split into two independent p ...

MMU, so operating system code dealing with memory protection and address translation is not generally portable. Enabling the MMU also costs a wait state on each memory access. While the SCC68070 is mostly binary compatible with the

, there is no equivalent chip in the

680x0 series. In particular, the SCC68070 is not a follow-on to the Motorola 68060. Even though the SCC68070 is a 32-bit processor internally, it has a 24-bit

address bus In computer architecture, a bus (shortened form of the Latin '' omnibus'', and historically also called data highway or databus) is a communication system that transfers data between components inside a computer, or between computers. This ex ...

, giving it a theoretical 16MB maximum RAM. However, this is not possible, as all of the on-board peripherals are mapped internally.

External links

xs4all.nl/~ganswijk/chipdir/reg/68070.txt
68k microprocessors {{compu-hardware-stub Microcontrollers Freescale Semiconductor Philips products