MC6840CP-G - 3-Channel Programmable Timer | Rochester
MPN: MC6840CP-G ✓ ActiveMC6840CP-G Overview
A programmable timer module is a timing IC that combines hardware counters with processor-accessible control and status registers. Within the hierarchy of timing and clock ICs, it sits below general-purpose clock and timer devices and provides a specialized timing subsystem for a processor bus. The MC6840 architecture allows software to program timing behavior instead of relying on fixed-delay logic or separate discrete counters.
The primary architectural feature is the bank of three 16-bit binary counters. Each counter has a corresponding control register, while the status register reports timer-related conditions to the host processor. This organization supports multiple independently configured timing events in one device, reducing the number of external timing components needed by an M6800-family controller. The verified source data does not provide operating voltage, clock frequency, output waveform, maximum count rate, package dimensions, temperature range, or absolute maximum ratings.
Typical legacy applications include industrial controller timing, data-acquisition sequencing, periodic service routines, programmable pulse generation, and event counting. In these systems, the timer module can provide repeatable time bases or interrupt requests, allowing the processor to divide software workload without implementing multiple independent counters in firmware. Because this is a legacy M6800-family component, system integration may also depend on processor-specific bus behavior and legacy development tooling.
Before designing a new board around the MC6840CP-G, engineers should obtain the complete Motorola MC6840CP datasheet and verify the processor interface, counter mode behavior, timing limits, and package-level pin assignments. The supplied distributor records confirm the product and its programmable timer function but do not establish a complete electrical specification table or a verified replacement list.
This product page combines the verified programmable-counter architecture, current distributor references, available pricing information, and practical sourcing guidance. It also distinguishes documented facts from parameters that still require confirmation from the original manufacturer datasheet, helping engineers assess the legacy timer module without inventing electrical, timing, or package data.
Drop-in alternatives for MC6840CP-G — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesMC6840CP-G Specifications
| Product Type | Programmable Timer Module (PTM) |
| Processor Family | Motorola M6800 family |
| Number of Counters | 3 counters |
| Counter Resolution | 16-bit binary |
| Control Registers | 3 control registers |
| Status Registers | 1 status register |
| Primary Function | Variable system time interval generation |
| Manufacturer of Original Device | Motorola, Inc. |
| Listing Brand | Rochester Electronics, LLC |
| Lifecycle Status | Active |
MC6840CP-G standard Pin Configuration Guide
Pin configuration for MC6840CP-G (standard package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for MC6840CP-G.
Refer to the datasheet for full pin configuration.
Typical Applications
MC6840CP-G is suitable for 6 applications: Legacy Industrial Controller Timing, Periodic Interrupt Generation, Programmable Event Counter, Data-Acquisition Sequencing, Programmable Pulse and Delay Generation, Legacy Equipment Repair.
Legacy Industrial Controller Timing
The MC6840CP-G fits an existing Motorola M6800-family industrial controller that requires repeatable service intervals without implementing multiple counters in software. Its three 16-bit binary counters and corresponding control registers can organize separate timing tasks, while the status register provides timer-state information to the processor. The key engineering task is to confirm the processor interface and counter limits from the complete datasheet; the supplied records establish the programmable-counter architecture but do not provide clock-frequency or supply-voltage limits. For maintenance and replication, retaining the original timing subsystem reduces software-validation risk compared with redesigning an obsolete control board.
Recommended
Periodic Interrupt Generation
MC6840CP-G is appropriate for a legacy processor system that must generate periodic interrupts for task scheduling or periodic service routines. Its three programmable 16-bit counters allow timing intervals to be distributed among multiple interrupt or event channels instead of forcing the processor to emulate every timer in software. The status register supports interaction between timer events and software handling. Designers must verify the counter clock source, reload behavior, interrupt polarity, and maximum count rate from the original Motorola datasheet because those values are not present in the supplied search records.
Recommended
Programmable Event Counter
The three 16-bit counters in the MC6840CP-G can support event-counting duties in legacy data-acquisition and sequencing equipment. A compatible M6800-family processor can configure a counter, monitor its state, and coordinate acquisition steps or external service events through the associated control and status registers. This arrangement reduces external counter hardware while preserving deterministic software access. Before implementing the circuit, verify allowable counter input frequency, edge sensitivity, overflow handling, and processor read timing; those specifications are not available in the supplied distributor snippets.
Recommended
Data-Acquisition Sequencing
MC6840CP-G can support timing sequences in legacy data-acquisition systems by dividing an overall acquisition process into programmable intervals. Each of the three 16-bit counters may correspond to a separate acquisition phase, supervisory interval, or timeout, while software reads the status register to coordinate subsequent operations. This architecture is especially useful when repairing equipment whose original CPU cannot economically manage multiple timing loops. Full implementation still requires the complete electrical table, especially supply voltage, counter timing limits, pinout, and processor-bus timing, which are not confirmed by the supplied records.
Recommended
Programmable Pulse and Delay Generation
The MC6840CP-G provides a hardware basis for programmable delays and periodic timing in legacy automation equipment. By configuring its three 16-bit counters and monitoring the status register, compatible processor firmware can generate repeatable sequencing intervals without long software delay loops. This can improve responsiveness in equipment that must service multiple time-based events. Engineers should consult the original datasheet to determine whether each counter directly drives an output or acts only through processor interrupts, and to establish minimum and maximum timing values before choosing component values or peripheral logic.
Recommended
Legacy Equipment Repair
MC6840CP-G is directly relevant to repairing or restocking an M6800-family controller whose original timer module has failed. Rochester Electronics is identified as the listed source, DigiKey references the exact ordering code, and LCSC reported the device in stock on 2026-10-28. Maintenance teams should preserve the original device only after comparing its Rochester ordering document with the installed package and pinout. Because the supplied data does not verify operating temperature, package, or electrical limits, board-level substitution should not be based on the MPN alone.
Recommended
Recommended Products Summary
Engineering reference data for MC6840CP-G — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Product Type | Programmable Timer Module (PTM) |
| Processor Family | Motorola M6800 family |
| Number of Counters | 3 |
| Counter Resolution | 16-bit binary |
| Control Registers | 3 |
| Status Registers | 1 |
| Brand | Rochester Electronics, LLC |
| Lifecycle Status | Active |
Key Differentiators
- Three independently programmable timing channels in one legacy timer device (vs Generic modern clock or timer IC without a verified pin-compatible source)
- Status-register support for processor-managed timer events (vs Discrete counter and latch implementation)
- Direct sourcing under the Rochester Electronics ordering code (vs Original Motorola MC6840CP legacy procurement channel)
Design Notes
Do not treat the MC6840CP family designation as complete proof that MC6840CP-G is electrically and mechanically interchangeable with every MC6840CP source. The supplied evidence confirms the programmable timer function but does not define the -G ordering suffix, package, temperature grade, or lead finish. Obtain the Rochester ordering information and compare it with the installed device before committing a replacement to a maintenance BOM.
Before laying out a replacement board, download the complete MC6840CP datasheet and verify the package drawing, all pin assignments, and processor-interface signals. The supplied records do not provide a verified pin count or pinout, so assigning pins from an informal schematic can create electrical or mechanical errors. Preserve the original component placement where possible and confirm any exposed pad, keep-out, or lead-finish requirements against the authoritative package drawing.
Validate the processor supply rail, timer input levels, and any counter or interrupt interface using the original MC6840CP electrical specifications. The verified source data does not state the operating voltage, input thresholds, power consumption, or absolute maximum ratings. During repair, measure the installed circuit rather than inferring these values, and maintain the original decoupling and signal-conditioning arrangement until equivalent performance has been demonstrated.
Compliance Information
The supplied source data does not state RoHS, REACH, lead-free, halogen-free, or conflict-minerals compliance. AEC-Q100 is not applicable because this is a legacy M6800-family programmable timer module rather than an automotive-qualified device designation.