A nonvolatile memory controller is disclosed that includes a read circuit configured to read memory cells of a nonvolatile memory device and a program and erase circuit configured to program and erase memory cells of the nonvolatile memory device. The nonvolatile memory controller includes a NAND shared algorithm circuit configured to communicate with the nonvolatile memory device so as to enter a test mode of the nonvolatile memory device and configured to modify the trim registers while the nonvolatile memory device is in the test mode such that the nonvolatile memory device performs one or more operations. The operations may include a suspendable program operation, a program suspend operation and an erase suspend operation.