Diodes Incorporated PI7C8952AFAE

Overview

PI7C8952AFAE from Diodes Incorporated is a PCI-bus dual UART IC with 128-byte transmit/receive FIFOs, supporting 450/550/950 enhanced modes, automated flow control, and crystal oscillator input at 1.8432 MHz or 2.048 MHz for precise baud rate generation. It serves as a serial interface bridge in embedded industrial controllers requiring reliable RS-232/422/485 communication.

For engineers reviewing the PI7C8952AFAE datasheet, PI7C8952AFAE pinout, PI7C8952AFAE application, or PI7C8952AFAE equivalent, key selection factors include PCI configuration register compatibility, dual-UART interrupt handling, FIFO trigger level programmability, and EEPROM-based configuration persistence across power cycles.

Technical Context

The PI7C8952AFAE implements two independent 16C550-compatible UART channels on a single PCI endpoint, with separate I/O and memory-mapped register access modes. Its PCI interface complies with PCI Local Bus Specification Rev 2.2, supporting Type 0 configuration space and standard memory/I/O transaction types.

Each UART channel features fully programmable baud rates (up to 1.5 Mbps), hardware/software flow control (XON/XOFF and RTS/CTS), and advanced diagnostics including global line status, overrun detection, and TX idle timeout counters - all accessible via dedicated registers in both I/O and memory-mapped modes.

Key Specifications

Pinout & Package

PI7C8952AFAE is housed in a 128-pin TQFP package (14 mm × 14 mm, 0.4 mm pitch) with exposed thermal pad for industrial temperature operation (–40°C to +85°C).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-PCI-UART applications.

Compared with XR17V352 and TL16C752B, PI7C8952AFAE uniquely balances PCI-native integration, EEPROM-persistent configuration, and 128-byte FIFOs - making it optimal for industrial PCI add-in cards where firmware simplicity, long-term supply stability, and minimal external components are prioritized.

Availability

PI7C8952AFAE is available at Aetrix Electronics and suitable for industrial PLC backplanes, retail POS terminals, medical data loggers, and automated test equipment requiring stable component supply and long-lifecycle support.

Supply support for PI7C8952AFAE 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and integrated circuits, headquartered in California and operating wafer fabrication, assembly, and test facilities worldwide.

The PI7C8952AFAE belongs to Diodes' PCI interface and serial communications product line, designed specifically for industrial and embedded systems requiring robust, standards-compliant bridging between legacy serial peripherals and modern PCI-based host platforms.

FAQ

What PCI specification revision does PI7C8952AFAE comply with?

The PI7C8952AFAE complies with PCI Local Bus Specification Revision 2.2. It supports Type 0 configuration space, memory-mapped and I/O-mapped access, and standard PCI transaction types including memory read/write, I/O read/write, and configuration read/write - verified in Section 6 of the official datasheet DS40347 Rev 3-2.

Does PI7C8952AFAE support both I/O and memory-mapped register access modes?

Yes, PI7C8952AFAE supports both I/O-mapped and memory-mapped register access. The mode is selected via the MODE pin at reset: low for I/O mode (base addresses defined in Table 7-1), high for memory-mapped mode (base address offset 0x1000). Each mode exposes identical UART functionality but with different address layouts and register offsets, detailed in Sections 7.2 and 7.3 of the datasheet.

How is the EEPROM used, and what configuration data does it store?

The on-chip 2-wire serial EEPROM stores non-volatile configuration parameters including PCI base address registers (BAR0/BAR1), UART mode selection (450/550/950), GPIO default states, and crystal frequency setting. This eliminates the need for BIOS or driver-level initialization at boot, enabling immediate UART operation after power-up - confirmed in Sections 8 and 11 of DS40347 Rev 3-2.

What is the maximum crystal frequency supported for baud rate generation?

The PI7C8952AFAE accepts only 1.8432 MHz or 2.048 MHz fundamental-mode crystals on XTAL1/XTAL2. These frequencies enable precise baud rate generation up to 1.5 Mbps with ±0.01% accuracy. Higher-frequency crystals are not supported - the internal PLL and divisor logic are fixed for these two values, as specified in Section 5.2.11 and Table 5-2 of the datasheet.