IBM 6589 - PC 365 - 32 MB RAM, Руководство пользователя

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Chapter 2. System Board Features
Keyboard and Mouse Ports
The keyboard-and-mouse subsystem is controlled by a general purpose 8-bit microcontroller. The
controller consists of 256 bytes of data memory and 2 KB of read-only memory (ROM).
The controller has two logical devices; one controls the keyboard, and the other controls the mouse. The
keyboard has two fixed I/O addresses and a fixed IRQ line and can operate without the mouse. The
mouse cannot operate without the keyboard because, although it has a fixed IRQ line, the mouse relies on
the addresses of the keyboard for operation. The following table shows the resource assignments for the
keyboard and mouse.
Note: When the computer is started, the resource assignments are subject to change during the
power-on self-test (POST).
The system board has one 6-pin connector for the keyboard port and another 6-pin connector for the
mouse port. For information on the connector pin assignments, see “Keyboard and Mouse Port
Connectors” on page 36.
General-Purpose I/O Ports
The system board has up to 16 general-purpose input/output (GPIO) pins, which are implemented by two
8-bit GPIO ports. The use of GPIO pins is dependent upon system design. Features of the GPIO ports
are:
Ÿ
Open-drain outputs with internal pull-ups and transistor-transistor logic (TTL) inputs
Ÿ
Software-configurable base address
Ÿ
Programmable direction
Ÿ
4-byte I/O address
Table 6. System Resource Assignments for the Keyboard and Mouse
System Resource Assignment
ROM None
RAM None
I/O (hex) 60, 64
IRQ 1 (keyboard), 12 (mouse)
DMA None
Chapter 2. System Board Features
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