| US 7,589,560 B2 | ||
| Apparatus for configuring I/O signal levels of interfacing logic circuits | ||
| David Glen Edwards, Dallas, Tex. (US); Brian Matthew Johnson, Allen, Tex. (US); Mark A. Shaw, Sachse, Tex. (US); and Stuart C. Haden, Lucas, Tex. (US) | ||
| Assigned to Hewlett-Packard Development Company, L.P., Houston, Tex. (US) | ||
| Filed on Oct. 19, 2006, as Appl. No. 11/583,322. | ||
| Prior Publication US 2008/0094106 A1, Apr. 24, 2008 | ||
| Int. Cl. H03K 19/0175 (2006.01); H03K 19/094 (2006.01); H03K 19/082 (2006.01) | ||
| U.S. Cl. 326—80 [326/62; 326/63; 326/81; 326/82; 326/83; 326/86; 326/90] | 19 Claims |
| 1. Apparatus for configuring input/output signal levels of interfacing logic circuits operating at different voltage levels,
said apparatus comprising:
a logic circuit for operating on a first printed circuit board (PCB) at a first voltage level;
a bank of input/output gates located on a second PCB and coupled to said logic circuit for interfacing input/output signals
at a second voltage level, different from said first voltage level, to said logic circuit located on said first PCB, said
bank of input/output gates including a port for Setting the operational voltage level thereof;
a control circuit coupled to said port and governed by a control signal to configure the operational voltage level of said
bank of input/output gates to render said first voltage level of said logic circuit located on said first PCB the same as
said operational voltage level of said interfacing input/output signals conducted by said bank of input/output gates located
on said second PCB;
a microcontroller operative to receive the first voltage level and a control signal from the first logic circuit; and
a digital-to-analog converter coupled to and receives the first voltage level and the control signal from said microcontroller
and provides the voltage level to the voltage regulator on the second PCB to serve as said operational voltage level of the
interfacing input/output signals.
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