Motorola 68040

Motorola 68LC040 with a clock frequency of 25 MHz.

That of a Motorola 68LC040 (XC68LC040RC33B).

Motorola 68040 with a clock frequency of 25 MHz.

That of a Motorola 68040 (XC68040RC25B).

The Motorola 68040 is a 32-bit microprocessor made by Motorola (later Freescale , now NXP ). It was launched in 1990 as the successor to the Motorola 68030 . The full version has two integrated memory management units (MMUs) (according to the Harvard architecture ) and an FPU (floating point unit) that is almost completely compatible with the Motorola 68881/68882 , as well as a level 1 cache of 4 KiB each for data and instructions. In the integer range , it achieves about twice as much as a Motorola 68030 with the same clock rate . The integrated FPU is more than twice as efficient as a Motorola 68882 . It follows the IEEE 754 floating point standard and does not contain any logic for trigonometric functions ; these must be simulated in software.

history

The Motorola 68040 was a popular microprocessor for high-end personal computers and workstations in the early 1990s , built into the newer versions of the NeXTcube and NeXTstation from NeXT , Apple Macintosh Quadra and Macintosh Performa, HP Apollo 400 series and Amiga 4000 .

Motorola was initially unable to meet the delivery date for the 68040; some manufacturers had to delay their products or, like HP, make other means: the HP Apollo 400t had already been announced, only the 68040 processor was still missing in quantities. The engineers quickly developed a daughterboard with a 68040-pin-compatible connector on which a Motorola 68030 and a Motorola 68882 sat at 50 MHz and 128 KiB L2 cache. This did not help Motorola's reputation in the industry, but the 68040 was popular with end customers because of its good price / performance ratio.

A variant of the 68040 is the Motorola 68LC040 without FPU. A variant of the Motorola 68EC040 without PMMU and FPU, with rudimentary memory management via four access control registers .

After the 68040, many computer providers did not switch to the successor Motorola 68060 , but switched directly to other processor platforms, such as PA-RISC in the case of HP and PowerPC at Apple.

variants

68040 LCVE- Complete CPU with FPU and MMU
68LC040 VE- FPU deactivated, MMU present
68EC040 LV- FPU and MMU
68040V LCE- "Low Voltage" version of the 68LC040

technical features

Working frequencies	10 MHz, 20 MHz, 25 MHz, 33 MHz, 40 MHz
Operating voltage	Vcore 5V Vcore 3.3V (68040V) I / O 5V
Working temperature	−40 ° C to 70 ° C
Manufacturing process	static CMOS 0.6 μm
Construction	CQUAD 184, PGA 179 FG, PGA 182
Data bus	32 bit
Address bus	32 bit
Instruction set	CISC
pipeline	6 stages
Cache	4 KiB DCache 4 KiB ICache 64 Entry ATC MMU Buffer (4-fold associative)
register	8 address registers 8 data registers 2 status registers 8 floating point data registers, each 80 bit wide 1 Floating Point Instruction Register 1 Floating Point Status Register 1 Floating Point Control Register
Transistors	≈1,170,000 (68040) ≈ 0.962,000 (68EC040) ≈ 0.813,000 (68LC040)
performance	≈29 Mips @ 40 MHz (The manufacturer's specification of 44 Mips is rather unrealistic) ≈11 MFlops @ 40 MHz

Web links

Commons : Motorola 68040 - collection of pictures, videos and audio files

Motorola 68040 processors: Pictures and descriptions on cpu-collection.de
(Motorola has outsourced chip production) Homepage of the manufacturer Freescale Inc. (English)
M68040 Microprocessors User's Manual (PDF; 3.30 MB; English)

Individual evidence

↑ M68040 Microprocessors User's Manual, Freescale Inc.

[1] M68040 Microprocessors User's Manual, Freescale Inc.