System on chip for enhancing quality of service and method of controlling the same
A system on chip (SOC) include at least one slave device, a plurality of master devices, a plurality of service controllers and an interconnect device. The master devices generate requests to demand services from the slave device, respectively. The service controllers generate urgent information signals and priority information signals for each of the master devices. The interconnect device is coupled to the slave device and the master devices through respective channels. The interconnect device performs an arbitrating operation on the requests based on the priority information signals and controls request flows between the slave device and the master devices based on the urgent information signals.
1. A system on chip (SOC) comprising:
at least one slave device:
a plurality of master devices configured to generate requests to demand services from the slave device, respectively;
a plurality of service controllers configured to generate urgent information signals and priority information signals for each of the respective master devices; and
an interconnect device coupled to the slave device and the master devices through respective channels, the interconnect device configured to perform an arbitrating operation on the requests based on the priority information signals and configured to control request flows between the slave device and the master devices based on the urgent information signals,
wherein the control of the request flows comprises blocking one of the request flows by masking at least one signal involved in a corresponding handshaking scheme,
wherein the interconnect device includes a limit signal generator configured to generate a limit signal based on at least one of the urgent information signals,
wherein at least one of the service controllers includes a limiter configured to block the one request flow between the corresponding master device and the interconnect device based on the limit signal,
wherein the limiter comprises:
a synchronizer configured to generate a synchronized limit signal based on the limit signal from the interconnect device; and
a mask unit configured to block the one request flow between the corresponding master device and the interconnect device based on the synchronized limit signal.
2. The SOC of claim 1 , wherein the limit signal generator is configured to generate the limit signal based on the urgent information signals that are generated by the service controllers except the service controller receiving the limit signal.
3. The SOC of claim 1 , wherein the synchronizer is configured to sample the limit signal in response to falling edges of a global clock signal of the interconnect device to generate the synchronized limit signal.
4. The SOC of claim 1 , wherein the mask unit comprises:
a first logic gate configured to output a masked valid signal by performing a logic operation on the synchronized limit signal and a valid signal from the corresponding master device; and
a second logic gate configured to output a masked ready signal by performing a logic operation on the synchronized limit signal and a ready signal from the interconnect device.
5. A method of controlling a system on chip (SOC) comprising at least one slave device, a plurality of master devices, a plurality of service controllers and an interconnect device, the slave device and the master devices coupled to the interconnect device through respective channels, the master devices generating requests to demand services from the slave device, respectively, the method comprising:
detecting at least one of bandwidths and latencies of the master devices based on operational characteristics of the master devices;
generating, urgent information signals and priority information signals based on at least one of the bandwidths and the latencies;
performing an arbitrating operation on the requests based on the priority information signals; and
controlling request flows between the slave device and the master devices based on the urgent information signals,
wherein the controlling comprises blocking one of the request flows by masking at least one signal involved in a corresponding handshaking scheme, and wherein the controlling further comprises:
generating, by the interconnect device, a limit signal based on at least one of the urgent information signals; and
blocking, by a limiter of one of the service controllers, the one request flow between the corresponding master device and the interconnect device based on the limit signal,
wherein the limiter comprises:
a synchronizer configured to generate a synchronized limit signal based on the limit signal from the interconnect device; and
a mask unit configured to block the one request flow between the corresponding master device and the interconnect device based on the synchronized limit signal.
6. The method of claim 5 , wherein the requests are transferred according to the handshake scheme that uses a valid signal and a ready signal, and
wherein controlling the request flows between the slave device and the master devices includes deactivating at least one of the valid signal and the ready signal based on the urgent information signals.
7. A system on chip (SOC) comprising:
at least one slave device:
a plurality of master devices configured to generate requests to demand services from the slave device, respectively;
a plurality of service controllers configured to generate urgent information signals and priority information signals for each of the respective master devices; and
an interconnect device coupled to the slave device and the master devices through respective channels, the interconnect device configured to perform an arbitrating operation on the requests based on the priority information signals and configured to control request flows between the slave device and the master devices based on the urgent information signals,
wherein the interconnect device includes a limit signal generator configured to generate a limit signal based on at least one of the urgent information signals,
wherein at least one of the service controllers includes a limiter configured to block the request flow between the corresponding master device and the interconnect device based on the limit signal, and
wherein the limiter comprises a synchronizer configured to generate a synchronized limit signal based on the limit signal from the interconnect device and a mask unit configured to block the request flow between the corresponding master device and the interconnect device based on the synchronized limit signal.