External bus controller
AssigneeOki Electric Industry Co., Ltd.
InventorMakoto Nagano
Life of this patent
Estimating the term…
Abstract
An external bus controller which is configured such that, when an external device having a data width smaller than that of an external bus is connected to the external bus, the signal lines of the external bus can be freely selected. This external bus controller comprises a first exchange, which converts the data width of input/output data so as to compensate for differences between the data width of the internal bus and the data width of an external device, and a second exchange, which exchanges signal lines between the first exchange and the used signal lines. The signal lines to be used are set for each external device using configuration pins or similar means.
Claims19
An external bus controller, comprising:
- a first exchange, which converts the width of data input from an internal bus so as to coincide with the data width of an external device connected to the external bus, and also converts the width of data input from said external bus so as to coincide with the data width of said internal bus;
- a recognition circuit, which recognizes, for each of said external devices, the signal lines connected to the input/output terminals of said external device among the signal lines of said external bus;
- a selector, which selects the signal lines to be used by said external bus according to the recognition result of said recognition circuit and a device specification signal;
- and,
- a second exchange, which outputs data input from said first exchange to signal lines selected by said selector, and also outputs data input from the signal lines to said first exchange.
Dependencies are inferred from the claim text.