Abstract: An interface for use of device whose core circuitry operates in one voltage domain, but exchanges signal with another device (or “host”) according a different voltage domain, and the use of such an interface for supplying data using a double data rate (DDR) transfer, is presented. One concrete example of this situation is a memory card, where the internal circuitry uses one voltage range for its core operating voltages, but exchanges signals with a host using different, input/output voltage range. According to a general set of aspects, the interface receives data signals from the device at the device's core operating voltage domain, individually level shifts these to the input/output voltage domain, and then combines them into a DDR signal for transfer to the host device, where a (non-level shifted) clock signal from the host device is used as the select signal to form the DDR data signal.

Abstract: An integrated circuit (IC) includes an output driver circuit portion that is electrically configurable, via a configuration input, to operate in either a first mode or a second mode corresponding to an indication of a condition of the IC, such as a supply voltage indication, the first mode and the second mode having different drive characteristics. A configuration interface circuit portion as part of the improved IC is adapted to selectively override the configuration input to configure operation of the output driver circuit portion in either the first mode or the second mode based on a drive strength control input, regardless of the condition of the IC.

Abstract: An integrated circuit (IC) includes an output driver circuit portion that is electrically configurable, via a configuration input, to operate in either a first mode or a second mode corresponding to an indication of a condition of the IC, such as a supply voltage indication, the first mode and the second mode having different drive characteristics. A configuration interface circuit portion as part of the improved IC is adapted to selectively override the configuration input to configure operation of the output driver circuit portion in either the first mode or the second mode based on a drive strength control input, regardless of the condition of the IC.