PC87591S

The National Semiconductor PC87591E, PC87591S and PC87591L are highly integrated, embedded controllers with an embedded-RISC core and integrated advanced functions. These devices are targeted for a wide range of portable applications that use the Low Pin Count (LPC) interface. The PC87591S is targeted for security applications and includes supporting hardware such as the Hardware Random Number Generator. The PC8591L replaces the on-chip flash with 4K of boot ROM for value solutions using shared BIOS architecture. "PC87591x" refers to all the devices.

The PC87591x incorporates National's CompactRISC CR16B PC87591S core (a high-performance 16-bit RISC processor), on-chip flash (ROM for the PC87591L) and RAM memories, system support functions and a Bus Interface Unit (BIU) that directly interfaces with optional external memory (such as flash) and I/O devices. System support functions include: WATCHDOG and other timers, interrupt control, general-purpose I/O (GPIO) with internal keyboard matrix scanning, PS/2® Interface, ACCESS.bus® interface, high accuracy analog-to-digital (ADC) and digital-to-analog converters (DAC) for battery charging, system control, system health monitoring and analog controls.

The PC87591x interfaces with the host via an LPC interface that provides the host with access to the Keyboard and embedded controller interface channels, integrated functions,

Real-Time Clock (RTC), BIOS firmware of PC87591S and security functions. Like members of National's SuperI/O family, the PC87591x is PC01 and ACPI compliant.