bbc_micro_keyboard.cdl File Reference

BBC microcomputer keyboard module. More...

Detailed Description

BBC microcomputer keyboard module.

Copyright (C) 2016-2017, Gavin J Stark. All rights reserved.

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at

http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.

CDL implementation of BBC microcomputer keyboard.

This module provides the logic that is in the BBC microcomputer keyboard - without the switches for the keys themselves.

The keyboard included a BCD counter and latch, so that the keyboard can auto-scan the keyboard columns and capture which column has a key pressed. Individual columns can also be explcitily scanned.

The 'keys down' information is clearly not possible to have here from physical keys, hence that data is provided by the t_bbc_keyboard bus in.

Namespaces
	bbc_micro_keyboard

Typedefs
typedef bit[8]	bbc_micro_keyboard::t_keys_pressed