C.1.12.6 RISC

The reset, interrupt, scan, and clock (RISC) ASIC implements four functions: reset, interrupt, scan, and clock. Generation and stretching of the reset pulse is performed in this ASIC. Interrupt logic concentrates 42 different interrupt sources into a 6-bit code, which communicates with the U2P ASIC. It also integrates a JTAG controller.

Highlights of the RISC ASIC features include:

• Determines system clock frequency

• Controls reset generation

• Performs PCI bus and miscellaneous interrupt concentration for U2P

• Controls flash PROM programming, frequency margining, and lab console operation

• 33-MHz operation

• 3.3-VDC and 5-VDC supply voltage