CY8C95xx | Cypress Semiconductor


The CY8C95xxA is a multi-port IO expander with on board user available EEPROM and several PWM outputs. All devices in this family operate identically but differ in IO pins, number of PWMs,and internal EEPROM size.

The CY8C95xxA operates as two I2C slave devices. The first device is a multi port IO expander (single I2C address to access all ports through registers). The second device is a serial EEPROM. Dedicated configuration registers can be used to disable the EEPROM. The EEPROM uses 2-byte addressing to support the 28 Kbyte EEPROM address space. The selected device is defined by the most significant bits of the I2C address or by specific register addressing.

The IO expander's data pins can be independently assigned as inputs, outputs, quasi-bidirectional input/outputs or PWM ouputs. The individual data pins can be configured as open drain or collector, strong drive (10 mA source, 25 mA sink), resistively pulled up or down, or high impedance. The factory default configuration is pulled up internally.

  1. Download and Install PSoC Designer™
  2. Purchase the CY3210-PSoCEval1
  3. Start your first PSoC designs
  4. Join the Cypress Developer Community.
User Module Datasheets
  • The silicon datasheet covers key features of the device, brief operational details, pin out, electrical specifications and characterization graphs. It only focuses on the silicon features. Analog  functions (for e.g. ADC, DAC) and Digital  functions (for e.g. PWM, timer) are documented in the .
  • The family errata documents operation deviation of device compared to the family datasheet. If certain feature doesn't work as expected it is documented in the errata document. It is very critical that user refers to corresponding errata document as it will document critical issues and workarounds for the device.
Programming Specifications
  • The PSoC® 1 In-System Serial Programming Specification provides programming timing and vectors so that developers and programmer vendors can create their own in-system programming solutions for a PSoC 1 device. The specifications are provided in 3 Application Notes (AN2026A/B/C) with 2 additional Application Notes (AN44168, AN59389) providing working easy to follow example code.
PSoC 1 Programmers
  • The General PSoC Programming web page is central location that details all aspects of programming related to all available PSoC devices like Software, Engineering Programmers, Programming Specifications and Production Programming Vendors.
Technical Reference Manual
  • The PSoC 1 Technical Reference Manual provides detailed information on the device features and how they work. It is intended for advanced user's who want to understand what's going on under the hood.


Getting Started
  • Click here for a user guide and introduction to Cypress Development Tools
General PSoC1 Kits The CY8CKIT-001 PSoC Development Kit
  • Cypress's PSoC® programmable system-on-chip architecture gives you the freedom to not only imagine revolutionary new products, but the capability to also get those products to market faster than anyone else.
    Featured Kit:
    The CY8CKIT-001 PSoC® Development Kit (DVK) provides a common development platform where you can prototype and evaluate different solutions using any one of the PSoC 1, PSoC 3, or PSoC 5 architectures. In addition, the kit includes several example projects with step-by-step instructions to enable you to easily get started developing PSoC solutions. This kit includes PSoC 1 (CY8C28xxx), PSoC 3 and 5 Family Processor Modules
CapSense CY3280-28xxx Universal CapSense Controller Board
  • The CapSense Family is Cypress’s market leading Capacitive Sensing solution that has replaced more than 3 Billion sensors with a Capacitive touch interface over the last many years.
    Featured Kit:
    The Universal CapSense Controller Kit CY3280-28xxx will provide customers with hardware to understand capacitive sensing and a software tool to set up and tune their project with minimal iterative code updates. The kits will also provide a platform for internal and external CapSense Plus™ training sessions, products evaluation, hardware/software validation.
Emulators PSoC1 Emulator Home Page The CY2315-DK IN-Circuit Emulation Development Kit
  • PSoC 1 devices require an In-Circuit Emulator (ICE) to perform debugging using the CY3215-DK In-circuit Emulation Development Kit. Cypress Semiconductor provides multiple POD foot options (PDIP, QFN, SSOP, SOIC). The POD kits are listed under the CY3210- XXXX or CY3250 – XXXX naming conventions. Visit the or click on the Title above to know more.
    Featured Kit: The CY2315 DK software interface allows the user to run, halt, and single step the processor code. It also allows the user to set complex event points. Event points can start and stop the trace memory on the ICE, as well as break the program execution.
    In addition to the CY3213 DK, different Emulation Pods are available to support the range of devices in the PSoC 1 family. They plug into (or are soldered onto) the user's circuit board to provide the physical interface. Pods are available for low-cost expansion of the ICE-Cube capability.