摘要:
A method, system and apparatus to provide a solution of PLL locking issue in the daisy chained memory system. A first embodiment uses consecutive PLL on based on locking status of backward device on the daisy chained memory system with no requirement of PLL locking status checking pin. A second embodiment uses Flow through PLL control with a locking status pin either using an existing pin or a separated pin. A third embodiment uses a relocking control mechanism to detect PLL relocking from the device. A fourth variation uses flag signal generation to send to the controller.
摘要:
An apparatus comprising a plurality of devices connected in series with one another, each of the devices comprising a test enable pin for receiving a test enable signal that indicates enablement of a test mode, and a test output pin for outputting a test output signal in the test mode, and a controller coupled to the devices and comprising an additional test output pin for outputting a test channel output signal, wherein a failure of at least one of the test output signals and the test channel output signal indicates the existence of one or more potential defects associated with the plurality of devices and the controller.
摘要:
A system includes a memory controller and a plurality of semiconductor devices that are series-connected. Each of the devices has memory core for storing data. The memory controller provides a clock signal for synchronizing the operations of the devices. Each device includes a phase-locked loop (PLL) that is selectively enabled or disabled by a PLL enable signal. In each group, the PLLs of a selected number of devices are enabled by PLL enable signals and the other devices are disabled. The enabled PLL provides a plurality of reproduced clock signals with a phase shift of a multiple of 90° in response to an input clock signal. The data transfer is synchronized with at least one of the reproduced clock signals. In the devices of disabled PLLs, the data transfer is synchronized with the input clock signal. The enabled PLL and disabled PLL cause the devices to be the source and the common synchronous clocking, respectively. The devices can be grouped. The devices of one group can be structured by multiple chip packages.