HP Vectra 500 Series - Manual (Page 54)

54
2 System Board - (SiS Chipset) (Part Number: D4051-63001)
Devices on the ISA Bus
Serial/Parallel Ports
The Super I/O chip supports two serial ports and one bidirectional parallel
port. The serial ports are high speed UARTs with 16-Byte FIFOs, and can be
programmed as COM1, COM2, COM3, COM4, or disabled.
The parallel port can operate in four modes:
• Standard mode (PC/XT, PC/AT, and PS/2 compatible)
• Bidirectional mode (PC/XT, PC/AT, and PS/2 compatible)
• Enhanced mode (Enhanced Parallel Port or EPP compatible)
• High speed mode (MS/HP Extended Capabilities Port or ECP
compatible).
It can be programmed as LPT1 (378h, IRQ7), LPT2 (278h, IRQ5), or
disabled.
16 Single-Bit General Purpose I/O ports
(GPIO) ❒ Modifiable addresses that are referenced by a 16-bit program-
mable register.
❒ Programmable direction for each signal (input or output).
❒ Programmable drive type for each output pin (open-drain or
push-pull).
❒ Programmable option for internal pull-up resistor on each input
pin.
❒ A back-drive protection circuit.
Clock source options ❒ Source is a 32.768 kHz crystal (an internal frequency multiplier
generates all the required internal frequencies).
❒ Source may be either a 48 MHz or 24 MHz clock input signal.
General features ❒ All accesses to the Super I/O chip activates a Zero Wait State
(ZWS) signal, except for accesses to the Enhanced Parallel Port
(EPP) and to configuration registers.
❒ Accesses to all configuration registers is through an Index and a
Data register, which can be relocated within the ISA I/O address
space.
❒ 160-pin Plastic Quad Flatpack (PQFP) package.
Function Features