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Microchip Technology AT89ISP
- Part No.:
- AT89ISP
- Manufacturer:
- Microchip Technology
- Category:
- Accessories
- Package:
- Datasheet:
-
AT89ISP.pdf
- Description:
- CABLE ISP PROGRAMMER 8051
- Quantity:
- Payment:
- Shipping:
Inventory:4,326
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Product details
Overview
AT89ISP from Atmel is a dedicated in-system programming (ISP) cable for AT89S and AT89LP microcontrollers, enabling serial reprogramming without device removal. It operates from 2.7V to 5.5V VCC, features a 25-pin parallel port interface and 10-pin IDC target header, and supports field updates for embedded control systems.
For engineers reviewing the AT89ISP datasheet, AT89ISP pinout, AT89ISP application, or AT89ISP equivalent, key considerations include voltage compatibility with target MCU supply rails, correct 10-pin header alignment (arrow-to-pin-1), SCK/MISO/MOSI signal routing, RST and SS (P1.4) connection requirements for AT89LP derivatives, and EPP-mode parallel port configuration.
Technical Context
The AT89ISP cable implements a passive-level-shifting serial ISP interface compliant with Atmel's proprietary ISP protocol over standard parallel port signaling. It delivers regulated target power (VCC) and provides bidirectional SPI signals - SCK, MISO, MOSI - plus RST and SS control lines.
It requires no onboard logic or firmware; signal translation relies on direct wiring and level tolerance of AT89S/AT89LP I/O pins. The cable mandates proper polarity alignment via arrow-marked 10-pin IDC header and specifies GND connections on pins 2 and 10 for noise immunity.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VCC Range | 2.7V–5.5V: Matches AT89S/AT89LP core supply range; enables direct power sourcing from target board without external regulator. |
| Interface Type | Parallel-to-SPI bridge: Converts EPP-mode parallel port handshaking into synchronous serial ISP commands. |
| Target Header | 10-pin male IDC: Standardized footprint for PCB-mounted receptacle; polarized design prevents misinsertion. |
| PC Interface | 25-pin DB-25 male: Connects directly to legacy PC parallel port; requires BIOS-configured EPP mode. |
| Signal Lines | SCK, MISO, MOSI, RST, SS, GND×2: Full 5-wire SPI + reset + dual ground for robust noise rejection. |
| SS Requirement | Mandatory for AT89LP (P1.4), optional for AT89S: Reflects architectural difference in single-cycle vs. traditional 8051 core timing. |
Availability
AT89ISP is available at Aetrix Electronics and suitable for embedded firmware update infrastructure, legacy 8051-based industrial controllers, and educational microcontroller labs requiring stable component supply and long-term toolchain continuity.
Supply support for AT89ISP includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Atmel Corporation (now part of Microchip Technology) designed and manufactured high-reliability microcontrollers, nonvolatile memory, and development tools for industrial, automotive, and consumer applications.
The AT89ISP belongs to Atmel's legacy 8051 programming tool ecosystem, engineered specifically to enable low-cost, field-deployable in-circuit reprogramming of AT89S and AT89LP families without socketing or UV erasers.
FAQ
What is the AT89ISP used for?
The AT89ISP is a hardware programming cable that enables in-system programming of Atmel AT89S and AT89LP microcontrollers via a PC's parallel port. It allows firmware updates, memory erasure, and device configuration without removing the MCU from the target board - critical for surface-mount designs and field maintenance. The AT89ISP eliminates mechanical wear from repeated IC insertion and supports rapid iteration during prototyping and production testing.
Does the AT89ISP require external power?
No, the AT89ISP draws regulated power (2.7V–5.5V) directly from the target board's VCC rail through pin 4 of its 10-pin header. It does not contain active circuitry or onboard regulators, so no external power supply or USB bus power is needed. This design ensures compatibility with the operating voltage of the connected AT89S or AT89LP device and simplifies setup in constrained environments where only the target board is powered.
Which microcontrollers are compatible with the AT89ISP?
The AT89ISP is explicitly designed for Atmel AT89S-series (e.g., AT89S51, AT89S52) and AT89LP-series (e.g., AT89LP2052, AT89LP4052) microcontrollers. Compatibility depends on correct pin mapping per Figure 4-1 and adherence to the ISP protocol timing. It is not compatible with AT89C or non-ISP-enabled 8051 variants, nor with newer AVR or ARM-based devices.
Why is the SS (Slave Select) pin required for AT89LP but not AT89S devices?
The SS pin (P1.4) is mandatory for AT89LP derivatives because their single-cycle 8051 core uses SS as a synchronization input during ISP entry, ensuring reliable boot-mode detection. AT89S devices use a different reset-and-clock sequence and do not require SS assertion. This functional distinction is documented in Atmel Application Note 3310E and must be observed when connecting the AT89ISP to avoid failed programming attempts.
Can the AT89ISP be used with modern laptops lacking a parallel port?
Yes - but only with a certified USB-to-parallel converter that fully emulates EPP mode (not just SPP or bi-directional modes). Atmel specifically recommends the DPiE SPP100 adapter. Generic USB–parallel adapters often fail due to timing inaccuracies or incomplete EPP register implementation, leading to communication timeouts or corrupted programming data. Verification against Atmel's software handshake requirements is essential before deployment.
AT89ISP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Packaging:
- Box
- Product Status:
- Obsolete
- Accessory Type:
- Cable - ISP (In-System Programming)
- For Use With/Related Products:
- AT89S, AT89LP MCUs
AT89ISP FAQ
1.How can I place an order for AT89ISP through Aetrix?
Please submit a Request for Quotation (RFQ) for AT89ISP on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for AT89ISP reliable?
The price and inventory of AT89ISP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT89ISP is usually 5 days.
3.What payment methods are accepted for AT89ISP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT89ISP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT89ISP?
AT89ISP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT89ISP order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for AT89ISP?
For technical support, including AT89ISP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT89ISP requirements.
6.How does Aetrix verify that AT89ISP is sourced from the original manufacturer or authorized distributors?
All AT89ISP products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that AT89ISP meets industry standards.
7.What is the process for return or replacement of AT89ISP?
All AT89ISP units undergo pre-shipment inspection (PSI). If there is an issue with AT89ISP, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The AT89ISP part is unused and in its original packaging.
Return procedure for AT89ISP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT89ISP Tags
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