PCI Express in microcontrollers was inevitable. One of the first examples to emerge is Applied Micro Circuits' PowerPC 440SPe. It's designed to be an I/O controller, so it sports PCI Express links for both host and device. Thus, it services a host processor with a PCI Express interface and external PCI Express peripherals. Target applications include RAID and SAN (storage-area network) servers.
The eight-channel, host-side PCI Express interface connects to a PCI Express host controller. A pair of four-channel PCI Express links connects to off-chip PCI Express peripherals. A parallel, 64-bit PCI-X bus interface is also available.
The 440SPe's 256-kbyte level 2 cache can be used as local SRAM. Applications requiring off-chip memory can utilize the dual-port, double-data-rate SDRAM controller. An external bus controller provides access to 8-bit, off-chip peripherals.
Peripherals include three serial ports, a pair of I2C ports, 32 general-purpose I/O (GPIO) ports, timers, and a 1-Gbit/s Ethernet interface with its own DMA controller. Dedicated DMA controllers also support intelligent I/O (I2O) of local peripherals and an XOR engine for parity generation and checking.
Applied Micro Circuits