Semiconductor device and reset control method in semiconductor device

摘要

Reset request from external are held at a reset request holding unit having holding units connected in series; a reset switching unit performs a logical product operation of all of outputs of the holding units to set it as an asynchronous reset request, setting an output of the holding unit at a final stage of the holding units as a synchronous reset request, performing a logical product operation of the asynchronous reset request and the synchronous reset request, and outputs an operation result; the asynchronous reset request is masked in a synchronous reset mode; and a reset signal is output from a reset output unit based on the operation result at the reset switching unit.

主权项

1. A semiconductor device, comprising:
a reset request holding unit configured to hold a reset request from external, wherein the reset request holding unit comprises a plurality of holding units connected in series; a reset switching unit configured to:
perform a first logical product operation of outputs of the plurality of holding units to set an operation result of the first logical product operation as an asynchronous reset request,set an output of the reset request holding unit at a final stage of the plurality of holding units as a synchronous reset request,perform a second logical product operation of the asynchronous reset request and the synchronous reset request,output an operation result of the second logical product operation, andmask the asynchronous reset request in a synchronous reset mode; a reset output unit configured to output a reset signal based on the operation result output from the reset switching unit; and a clock switching unit configured to switch based on whether a first clock is supplied to the reset request holding unit in response to the reset signal being asserted or a second clock is supplied to the reset request holding unit in response to the reset signal being absent, wherein the plurality of holding units of the reset request holding unit is configured to operate based on the clock supplied from the clock switching unit.