| 摘要 |
The invention relates to a method and a circuit for carrying out a trimming operation on integrated circuits (2) having a trimming circuit portion (1) which includes memory elements (10) and a means (8) of modifying the state of said memory elements (10), at least a first input or supply pin (IN), an output pin (OUT), and a second supply pin (GND). The method comprises the following steps: enabling a single pin (OUT) to receive trimming data by biasing the pin to outside its operating range; to acquire such data, obtaining a clock signal from a division of the bias potential of the trimming pin (OUT); obtaining the logic value of the trimming data from a different division of the bias potential of said pin (OUT); enabling serial acquisition of the data according to the clock signal; and transferring the data to the means (8) of modifying the state of the memory elements (10). Advantageously, the data are also transferred into a selection logic (11), by-passing the means (8) for modifying the state of the memory elements (10), on the occurrence of a simulated trimming operation. <IMAGE> |
