CSG 65CE02

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CSG 65CE02
ProducedFrom 1988 to 1988
Common manufacturer(s)
Max. CPU clock rate2 MHz to 10 MHz
Instruction set6502

The CSG 65CE02 is an 8/16-bit microprocessor developed by Commodore Semiconductor Group in 1988.[1] It is a member of the MOS Technology 6502 family.


CSG 65CE02 registers
15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 00 (bit position)
Main registers
  A Accumulator
Index registers
  X X index
  Y Y index
  Z Z index
SPH SPL Stack Pointer
  B Base Page
Program counter
PC Program Counter
Status register
  N V E B D I Z C P Processor flags
CSG 65CE02 pin-out

The 65CE02 is an improved version of the 6502. It is fabricated using 2 µm CMOS technology, allowing for lower power operation compared to previous NMOS and HMOS versions of the 65xx family. It is housed in a 40-pin DIP that is pin compatible with the 6502.[2]

Internally, the pipeline of the 65CE02 was redesigned to reduce the number of cycles required to execute an instruction. The 65CE02 can recover faster from engagement of the SYNC signal, which reduces the minimum instruction execution time from 2 cycles to 1 cycle.[3] These improvements allow the 65CE02 to execute code up to 25% faster than previous 65xx models.[2]

Additionally, a third index register (Z) was included, the stack pointer was widened to 16 bits, and the zero page addressing mode was superseded by the more flexible direct page addressing mode.[2]

The 65CE02 uses a superset of the Rockwell 65SC02 instruction set. In addition to the enhancements and bug fixes included in the 65SC02, the 65CE02 includes new instructions for indirect jumps (allows the use of jump tables), 16-bit branches, bit shifting (ASR) and stack relative loads/stores. Several read-modify-write memory instructions (ASL/DEC/INC/PSH/ROR) were enhanced to support 16-bit values. Lastly, instructions supporting the new registers were added.

Like the original 6502, the 65CE02 does not include bank switching support. Only 64KB of RAM can natively be accessed. Larger memory configurations require the use of an external MMU.

CSG 4510[edit]

CSG 4510

The 4510 is a system in package (SiP) variant of the 65CE02 that includes two 6526 CIA I/O port controllers. It is housed in an 84-pin PLCC.[4]


The 65CE02 was used in the Commodore A2232 serial port card for the Amiga computer.[5][6] The 4510 was used in the unreleased Commodore 65 home computer [7] and the unreleased Commodore CDTV cost-reduced revision.[7][8]

See also[edit]


  1. ^ "MOS 65CE02 Microprocessor Data Sheet" (PDF).
  2. ^ a b c "Commodore Semiconductor Group CSG65CE02 Technical Reference". zimmers.net. 2009-08-18. Retrieved 2013-06-21.
  3. ^ "US patent 5088035: System for accelerating execution of program instructions by a microprocessor".
  4. ^ "Amiga Stuff: 4510 Hardware Info".
  5. ^ "Amiga Stuff: 65CE02 Hardware Info".
  6. ^ "Big Book of Amiga Hardware: Commodore A2232".
  7. ^ a b "Commodore Knowledge Base: The Commodore 65".
  8. ^ "Amiga Hardware Database: CDTV II".

External links[edit]