US-20260128758-A1 - SEMICONDUCTOR DEVICE AND COMMUNICATION SYSTEM

Abstract

A semiconductor device includes a receiver configured to externally receive communication data by serial communication, and a controller. In the semiconductor device, its group is settable. The communication data includes first data indicating whether broadcasting is in progress and second data indicating the group of a semiconductor device. If the group set in the controller’s own semiconductor device matches the group indicated by the second data, the controller judges that broadcasting is in progress for the controller’s own semiconductor device.

Inventors

• Kei Nagao

Assignees

• ROHM CO., LTD.

Dates

Publication Date

20260507

Application Date

20251230

Priority Date

20230706

Claims (9)

1. 1 . A semiconductor device comprising: a receiver configured to externally receive communication data by serial communication; and a controller, wherein, in the semiconductor device, a group thereof is settable, the communication data includes: first data indicating whether broadcasting is in progress; and second data indicating a group of a semiconductor device, and, if the group set in the controller’s own semiconductor device matches the group indicated by the second data, the controller judges that the broadcasting is in progress for the controller’s own semiconductor device.
2. 2 . The semiconductor device according to claim 1 , wherein, if the first data indicates that not broadcasting but normal access is in progress, the second data indicates a device address of a semiconductor device that is a target.
3. 3 . The semiconductor device according to claim 1 , wherein, if the first data indicates that broadcasting is in progress, the second data can be set so as to indicate that broadcasting is in progress for all semiconductor devices that receive the communication data.
4. 4 . The semiconductor device according to claim 1 that is connectable via a first bus to a transmitter provided outside and that is connectable via a second bus to a device provided outside, the semiconductor device comprising: a first receiver configured to be capable of receiving the communication data from the transmitter via the first bus; and a first transmitter configured to be connectable to the device via the second bus, wherein the first receiver and the first transmitter are configured such that, if bridging selection data included in the communication data indicates that intact outputting is on to output bit data intact between the first and second buses, data corresponding to a protocol of the device included in the communication data is output intact to the second bus.
5. 5 . The semiconductor device according to claim 4 , wherein, if the bridging selection data indicates that the intact outputting is off, the first data indicates whether the broadcasting is in progress, and, if the bridging selection data indicates that the intact outputting is on, the first data indicates a parity bit.
6. 6 . The semiconductor device according to claim 1 , wherein the first and second data are included in a same frame in the communication data along with bit data indicating a read or a write.
7. 7 . The semiconductor device according to claim 1 further comprising: a register, wherein the group is settable based on setting data stored in the register.
8. 8 . A communication system comprising: the semiconductor device according to claim 1 ; and a transmitter configured to transmit the communication data, wherein, with semiconductor devices with a same register map taken as semiconductor devices of a same type, a plurality of the semiconductor devices are provided for each of different types of the semiconductor device.
9. 9 . The communication system according to claim 8 , wherein the semiconductor devices of the same type are arranged on, so as to be distributed among, a plurality of substrates.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This nonprovisional application is a continuation application of International Patent Application No. PCT/JP2024/021377 filed on June 12, 2024, which claims priority to Japanese Patent Application No. 2023-111351 filed on July 6, 2023, the entire contents of which are hereby incorporated by reference. TECHNICAL FIELD The present disclosure relates to a semiconductor device and a communication system. BACKGROUND ART Semiconductor devices with a serial communication function are used in various applications. Patent Document 1 discloses one example of a circuit technology relating to serial communication. Citation List Patent Literature Patent Document 1: JP 2017-224946 A1 BRIEF DESCRIPTION OF DRAWINGS [FIG. 1] FIG. 1 is a diagram showing the configuration of a communication system according to an illustrative embodiment of the present disclosure. [FIG. 2] FIG. 2 is a block diagram of a semiconductor device according to the illustrative embodiment of the present disclosure. [FIG. 3] FIG. 3 is a register map relating to the grouping function in a register in the semiconductor device. [FIG. 4] FIG. 4 is a diagram showing one example of the correspondence between values of group setting data and groups to be set. [FIG. 5] FIG. 5 is a diagram showing one example of grouping of semiconductor devices. [FIG. 6] FIG. 6 is a diagram showing a data structure of reception data RX in a case where a write is performed with a semiconductor device as the target device. [FIG. 7] FIG. 7 is a diagram showing one example of the correspondence between the values of device addresses and group designation for broadcasting. [FIG. 8] FIG. 8 is a flowchart showing one example of steps of broadcasting. [FIG. 9] FIG. 9 is a diagram showing the data structure of the reception data RX in a case where a device is accessed using a bridging function. [FIG. 10] FIG. 10 is a timing chart showing communication control performed when a write is performed to a device. [FIG. 11] FIG. 11 is a timing chart showing communication control performed when a read is performed from a device. DESCRIPTION OF EMBODIMENTS Detailed Description Now, an illustrative embodiment of the present disclosure will be described with reference to the accompanying drawings. 1. Communication System FIG. 1 is a diagram showing the configuration of a communication system 70 according to an illustrative embodiment of the present disclosure. The communication system 70 includes an MCU (micro controller unit) 20, a CAN (controller area network) transceiver 30, a CAN transceiver 40, a semiconductor device 1, N devices 10 (where N is an integer of one or more), a plurality of semiconductor devices 50, and a plurality of semiconductor devices 60. The communication system 70 is, for example, for use on board a vehicle. A CAN transceiver 40, a semiconductor device 1, devices 10, and semiconductor devices 50 are mounted on a first substrate PB1. A CAN transceiver 40, a semiconductor device 1, devices 10, and semiconductor devices 60 are mounted on a second substrate PB2. Between the MCU 20 and CAN transceiver 30, communication is performed using UART (universal asynchronous receiver/transmitter). UART is a protocol for exchanging serial data between two devices. In UART, bidirectional communication is performed across two lines between the transmission side and a reception side. Between the CAN transceivers 30 and 40, communication is performed across a CAN bus 35. CAN is a serial communication protocol standardized in an international standard like ISO 11898. The CAN transceiver 30 has a TXD (transmission data input) terminal 30A and an RXD (reception data output) terminal 30B. The CAN transceiver 30 outputs, to the CAN bus 35, data input to the TXD terminal 30A, and outputs, from the RXD terminal 30B, data input from the CAN bus 35. On the first substrate PB1, the CAN transceiver 40 and semiconductor device 1 and semiconductor devices 50 are connected together across a bus BS1. The bus BS1 is used for UART communication. The CAN transceiver 40 has an RXD terminal 40A and a TXD terminal 40B. The CAN transceiver 40 outputs, to the CAN bus 35, data input to the TXD terminal 40B, and outputs, from the RXD terminal 40A, data input from the CAN bus 35. The semiconductor device 1 is an IC (integrated circuit) that has integrated in it a circuit with a predetermined function and is configured as, for example, an LED (light-emitting diode) driver IC. The semiconductor device 1 has an RX (reception data input) terminal 1A and a TX (transmission data output) terminal 1B. The plurality of semiconductor devices 50 are ICs having integrated in them a circuit with the same function as or a different function from the semiconductor device 1. Like the semiconductor device 1, the semiconductor devices 50 have an RX terminal 50A and a TX terminal 50B. The RX terminals 1A and 50A are both connected to the RXD terminal 40A. The TX terminals 1B and 50B are both con