thumb|A Motorola 68EC060 microprocessor

The Motorola 68060 ("sixty-eight-oh-sixty") is a 32-bit microprocessor from Motorola released in April 1994. It is the successor to the Motorola 68040 and is the highest performing member of the 68000 series. The 68060 is the last development of the 68000 family for general purpose use, abandoned in favor of the PowerPC chips. Two derivatives were produced, the 68LC060 (low cost) which lacked the floating-point unit (FPU) and the 68EC060 (embedded controller) which removed both the FPU and memory management unit (MMU).

Architecture

There is an LC (Low-Cost) version, without an FPU and EC (Embedded Controller), without MMU and FPU. The 68060 design was led by Joe Circello.

The 68060 shares most architectural features with the P5 Pentium. Both have a very similar superscalar in-order dual instruction pipeline configuration, By the arrival of the 68060, however, the company had already announced its adoption of PowerPC, developed by IBM and Motorola, prior to the availability of the 68060.

Upon introduction of low-power variants of the 68040 and other devices, Motorola anticipated that Apple might leave a space in its product range for 68060-based products, giving the company "a high performance hedge in case the transition to RISC proves problematic". In late 1992, Apple chairman John Sculley had indicated usage of the 68060 in server products from 1993, followed up by products based on PowerPC from 1994. With the 68060 only arriving in 1994, the Apple Workgroup Server range ultimately transitioned from products based on the 68040 directly to those employing PowerPC processors.

The 68060 was introduced at 50 MHz on Motorola's 0.6 μm manufacturing process. A few years later it was shrunk to 0.42 μm and clock speed raised to 66 MHz and 75 MHz. Some users managed to overclock rev6. 68060 CPU-s (mask: 71E41J) up to 120 or 133 MHz. Benchmarking of the 50 MHz 68060 fitted in accelerator cards for the Commodore Amiga indicated Dhrystone 2.1 benchmark results of around 80,000 Dhrystones per second, this being broadly comparable to a Sun SPARCstation 10 workstation.

Developments of the basic core continue, intended for embedded systems. Here they are combined with a number of peripheral interfaces to reduce the overall complexity and power requirements of a design. A number of chips, each with different sets of interfaces, are sold under the names ColdFire and DragonBall.

History

Model numbers with even second-to-last digit (68000, 68020, 68040, 68060) were reserved for major revisions to the 680x0 core architecture. Model numbers with odd second-to-last digit (68010, 68030) were reserved for upgrades to the architecture of the previous chip. Motorola never produced a 68050.

In desktops, the 68060 is used in some variants of the Amiga 4000T produced by Amiga Technologies, and available as a third party upgrade for other Amiga models. It is also used in the Amiga clone DraCo non-linear video system.

Medusa Computer Systems of Switzerland introduced the Hades 060 computer in 1996, aiming for compatibility with the Atari ST family of systems, featuring a 68060 core at 120 MHz, a 30MHz bus, 4 MB (EDO or SIM) RAM upgradeable to 1 GB, 2 ISA slots, 4 PCI slots, 1 VME slot, and 1 E-IDE slot. In graphical terms, the computer could manage ATI 64, ET 4000 and ET 6000 graphic cards at 135 MHz (with 2 or 4 MB). A modified TOS 3.06 was used, with MultiTOS possible and NVDI. The Hades 060 followed on from the earlier Medusa T60 system.

The Q60 extended the Sinclair QL design similarly from the slowest start to the ultimate pace of the 68K architecture's capabilities; these 68060-based motherboards—at 66 MHz for the full 68060 or a non-FPU 68LC060 option overclocked to 80 MHz—are more than 100 times faster than the Sinclair QL while running the same operating systems.

The 68060 was used in Nortel Meridian 1 Option 51, 61 and 81 large office PBX systems, powering the CP3 and CP4 core processor boards. A pair of these boards each sporting a 68060 could be used to make the PBX fault tolerant. This was a logical application as previous Meridian 1 cores used other Motorola chips. Nortel later changed the architecture to use Intel processors.

A 68060 processor upgrade to Wellfleet Communications' Backbone Concentrator Node (BCN) router was announced in 1995.

The Motorola Vanguard 6560 multiprotocol router uses a 50 MHz 68EC060 processor.

Motorola MVME-17x and Force Computer SYS68K VMEbus systems use a 68060 CPU.

Alpha Microsystems AM-6000, AM-6060, and AM-7000 use a 68060. After Motorola stopped developing newer processors, Alpha Microsystems migrated to x86.

Variants

68EC060

The 68EC060 is a version of the Motorola 68060 microprocessor, intended for embedded controllers (EC). It differs from the 68060 in that it has neither an FPU nor an MMU. This makes it less expensive and it draws even less power.

68LC060

The 68LC060 is a low cost version of the Motorola 68060 microprocessor with no FPU. This makes it less expensive and it draws less power.

Feature table

{| class="wikitable"

|-

! Variant !! MMU !! FPU !! Max Frequency

|-

| 68060 || || || 75 MHz or 133 MHz overclocked

|-

| 68LC060 || || || 75 MHz or 133 MHz overclocked

|-

| 68EC060 || || || 75 MHz or 133 MHz overclocked

|}

Technical data

{| class="wikitable"

|-

| CPU clock rate

| Officially: 50, 60, 66, 75 MHz

Overclocked: 66 (rev1-2), 80 (rev3-4), 110, 120, 133 and 150 MHz (rev5-6)

|-

| Voltage supply ||

  • Vcore 3.3 V
  • I/O 5 V

|-

| Temperature

| ( with the current mask)

|-

| Logic family

| Static CMOS<!--Full or partial?-->

|-

| Production process

| CMOS and later

|-

| Chip carrier

| PGA 206 (compatible with 68040), TBGA 304 31*31*1.7P1.27

|-

| Address bus

| 32 bit

|-

| Data bus

| 32 bit

|-

| Instruction set

| CISC

|-

| Cache ||

  • DCache ()
  • ICache ()
  • FIFO Instruction Buffer
  • 256 Entry Branch Cache
  • 64 Entry ATC* MMU Buffer (4-way associative)

|-

| Register ||

  • 10 for Address operations (7 gen., 2 stack, 1 pc)
  • 8 for Data operations
  • 1 for CPU flags (status register)

|-

| Transistors

|

|-

| Performance ||

  • ~67 MIPS @ 50 MHz
  • ~88 MIPS @ 66 MHz
  • ~110 MIPS @ 75 MHz
  • ~36 MFlops @ 66 MHz
  • ~160 MIPS @ 120 MHz
  • ~177 MIPS @ 133 MHz (estimate)
  • ~200 MIPS @ 150 MHz (estimate)