MC6840CP - Three-Channel Programmable Timer | Motorola
MPN: MC6840CP ✗ End of LifeMC6840CP Overview
A programmable timer module is a peripheral category that generates timed events, measures intervals, counts external events, and coordinates periodic interrupts in a processor-based system. In the M6800 ecosystem, the MC6840 extends the processor with hardware timing functions that would otherwise require software loops, external counters, or additional logic. Its three counters make it useful for several independent timing tasks within one component.
The three 16-bit binary counters are the central architectural feature identified by the Motorola datasheet result. Each counter corresponds to a control register, allowing firmware to select operating behavior, while the status register supports observation of timer events. Specific counter modes, clock inputs, interrupt outputs, read/write timing, and maximum operating frequency require confirmation from the manufacturer datasheet because those details are absent from the supplied verified snippets.
Typical legacy applications include periodic service routines, elapsed-time measurement, pulse generation, event counting, industrial-control timing, and M6800-family test equipment. In each case, firmware configures the relevant counter, polls or receives a timer indication, and uses the resulting event for control flow or measurement. The hardware timer reduces processor workload, but software must still initialize each control register and interpret status correctly.
The key design consideration is verification of interface details. Before schematic capture or PCB layout, engineers should obtain the original manufacturer datasheet and confirm the exact CP package, pin assignments, signal names, voltage ratings, timing limits, and environmental specifications. Search results include an MC6840CP-G listing from Rochester Electronics, but the suffix and source do not establish that MC6840CP and MC6840CP-G are electrically, mechanically, and pin-for-pin interchangeable.
This page combines the verified Programmable Timer Module description, three-counter architecture, distributor evidence, and sourcing links with explicit uncertainty markers. It distinguishes verified facts from missing electrical, package, pinout, pricing-tier, and lifecycle data rather than inferring specifications that are not present in the supplied sources.
Drop-in alternatives for MC6840CP — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
No drop-in alternatives available for this product.
Request AlternativesMC6840CP Maximum Ratings & Electrical Characteristics
| Product Type | Programmable Timer Module (PTM) |
| Processor Family | M6800 Family |
| Counter Count | 3 counters |
| Counter Width | 16 bits each |
| Counter Type | Binary counter |
| Control Register Count | 3 registers |
| Status Register Count | 1 register |
| Primary Function | Variable system time interval generation |
MC6840CP standard Pin Configuration Guide
Pin configuration for MC6840CP (standard package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for MC6840CP.
Refer to the datasheet for full pin configuration.
Typical Applications
MC6840CP is suitable for 6 applications: Periodic Service Interrupts, Elapsed-Time Measurement, Pulse and Tone Generation, External Event Counting, Legacy Industrial Control, Test and Measurement Sequencing.
Periodic Service Interrupts
The MC6840CP fits periodic service timing in an M6800-based controller because the verified architecture provides three programmable 16-bit counters designed to establish variable system time intervals. Firmware can dedicate one counter to a recurring scheduler while using the other counters for deferred tasks. This hardware approach is more deterministic than relying on a software-only delay loop, although exact reload behavior, interrupt outputs, and counter timing must be verified in the original Motorola datasheet.
Recommended
Elapsed-Time Measurement
The MC6840CP can support elapsed-time measurement by using one of its three 16-bit binary counters to accumulate events from a known time base. A control program can record the counter value at start and completion, calculate the interval, and report the result to the surrounding M6800 system. The supplied data confirms the counter width and programming architecture but does not identify scaling behavior, read-locking rules, overflow treatment, or clock limits, all of which require datasheet confirmation.
Recommended
Pulse and Tone Generation
A programmable timer module can generate defined timing intervals or repeated output waveforms, making the MC6840CP relevant to pulse-generation and legacy tone-generation circuits. The three independent counters allow separate waveform periods without multiplying peripheral packages. Before implementation, engineers must verify which counter modes generate pulses, whether outputs are programmable, how frequency is calculated, and what output rise and fall timing applies; those details are not present in the verified snippets.
Recommended
External Event Counting
The MC6840CP's three programmable counters can potentially count external events when the selected counter mode and clock path are confirmed. This use suits production-line indexing, batch counting, and actuator-position tracking where an M6800 processor needs repeatable event totals. The supplied source establishes three 16-bit counters and corresponding control registers but does not state input pulse-width limits, edge sensitivity, input levels, or counter cascading behavior, so the full interface specification is required before hardware design.
Recommended
Legacy Industrial Control
MC6840CP is applicable to maintenance or continuation of M6800-family industrial equipment that requires programmable time intervals alongside legacy processor logic. Its three counters can support multiple independent schedules such as actuator delays, scan timing, and status sampling. A redesign should preserve the original bus and pin interface where possible, but the verified material does not establish the package, processor bus signals, control-register behavior, or environmental grade. Those constraints must be closed before claiming a drop-in recovery.
Recommended
Test and Measurement Sequencing
The MC6840CP can serve as a timing coordinator in M6800-based test equipment by scheduling stimulus, acquisition, and reporting events across its three counters. Independent 16-bit channels provide more flexibility than a single event interval and can reduce software coordination. However, deterministic response time, counter synchronization, status-bit behavior, and interrupt latency are not supplied in the verified data. Those characteristics must be measured or obtained from the datasheet before use in safety- or timing-critical production systems.
Recommended
Recommended Products Summary
Engineering reference data for MC6840CP — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product |
|---|---|
| Product Type | Programmable Timer Module (PTM) |
| Processor Association | M6800 Family |
| Counter Count | 3 |
| Counter Width | 16 bits each |
| Control Registers | 3 corresponding control registers |
| Status Register | 1 |
| Brand | Motorola |
Key Differentiators
- Three independent timer channels (vs MC6840CP-G)
- Designed for the M6800 processor family (vs Generic modern microcontroller)
- Dedicated control and status architecture (vs Software timing loop)
Design Notes
Do not assume that MC6840CP and MC6840CP-G are interchangeable merely because their base numbers are similar. The verified search results do not provide a package drawing, pin table, electrical-limit comparison, or cross-reference statement. Download the applicable manufacturer or authorized-source document for each exact suffix, compare every physical and logical signal, and obtain written supplier confirmation before substituting the Rochester Electronics device.
Supply-voltage design cannot be completed from the supplied data because no operating-voltage range or absolute-maximum ratings are included. Before connecting an M6800-family system, verify VCC limits, input thresholds, output levels, power dissipation, and decoupling requirements in the original datasheet. Do not infer 5 V compatibility from the age or family of the device, and do not substitute modern-level logic without an explicit interface-level comparison.
The verified data does not identify the CP package dimensions or pin count. Therefore, no footprint should be released solely from the MPN suffix or from generic historical assumptions. Use the exact package drawing and pin table from the manufacturer document, inspect lead pitch and row spacing, and verify every signal against the schematic before layout. Legacy packages may require constraints or manual library review that modern automated tools do not flag.
Firmware must initialize and interpret the three control registers and status register according to the manufacturer-defined counter modes. Avoid coding from the names alone: define how each counter is clocked, started, stopped, read, cleared, and reloaded, including overflow behavior. Establish a short hardware test that exercises all three channels independently and verifies the status flags under expected timing and load conditions.
Compliance Information
The supplied sources do not state RoHS, REACH, lead-free, halogen-free, or conflict-mineral compliance. AEC-Q100 is not applicable to the documented timer function, but no automotive qualification claim is supported.