Koninklijke Philips Corporation N.v.

Nxp B.v.

Richard Fabbri

Neil Edward Birns

William J Slivkoff

Hong Bin Hao

Jie Zheng

A device that supports a plurality n of message objects, including a plurality of registers associated with each message object, including at least one object match ID register that contains a multi-bit object match ID field, and at least one object mask register that contains a multi-bit object mask field; and, a CAN/CAL module that processes incoming messages. The CAN/CAL module assembles a multi-bit screener ID from selected bits of each incoming message to be acceptance filtered, compares the bits comprising the screener ID with corresponding bits of the object match ID field associated with each of at least designated ones of the message objects, disregarding any bits of each object match ID field that are masked by corresponding bits of the associated object mask field, and then determines whether any of the comparisons results in a match.

CAN device featuring advanced can filtering and message acceptance

A CAN device that supports a plurality n (where n&gE;3) of message objects, including a plurality of registers associated with each message object, including at least one object match ID register that contains a multi-bit object match ID field, and at least one object mask register that contains a multi-bit object mask field; and, a CAN/CAL module that processes incoming messages. The CAN/CAL module assembles a multi-bit screener ID from selected bits of each incoming message to be acceptance filtered, compares the bits comprising the screener ID with corresponding bits of the object match ID field associated with each of at least designated ones of the plurality n of message objects, disregarding any bits of each object match ID field that are masked by corresponding bits of the associated object mask field, and then determines whether any of the comparisons results in a match. Any selected one or more bits of the object match ID field associated with each of the plurality n of message objects can be set to '1' or '0', and any selected one or more bits of the object mask field associated with each of the plurality n of message objects can be set to &lsquo;1&rsquo; or &lsquo;0&rsquo; in order to mask any selected one or more bits of the associated object match ID field, whereby the combination of the object match ID field and the object mask field associated with each of the plurality n of message objects constitutes a fully programmable match and mask filter. The CAN/CAL module has the capability to perform acceptance filtering on incoming messages constituting either standard or extended CAN frames. If more than one match is detected, a lowest-numbered (or, alternatively, highest-numbered) one of the message objects is designated to be the matching message object.

Can device featuring advanced can filtering and message acceptance

A CAN microcontroller that supports a plurality of message objects, the CAN microcontroller including a processor core that runs CAN applications, a CAN/CAL module that processes incoming messages, and a plurality of message buffers associated with respective ones of the message objects, each message buffer having a size and a location that are programmable. The CAN microcontroller also includes a data memory space. Preferably, the plurality of message buffers are located in the data memory space, which may include both an on-chip portion and an off-chip portion. The plurality of individual message object registers associated with each of the message objects contain fields of command/control information that facilitate configuration and setup of that message object. Preferably, the plurality of individual message object registers associated with each message object include at least one buffer size register that contains a message buffer size field that enables the size of the message buffer associated with that message object to be programmed, and at least one buffer location register that contains a message buffer location field that enables the location of the message buffer associated with that message object to be programmed.

Can microcontroller that employs reconfigurable message buffers

A CAN microcontroller that supports a plurality of uniquely-numbered message objects, that includes a processor core that runs CAN applications, a plurality of message buffers associated with respective ones of the message objects, and a CAN/CAL module. The CAN microcontroller further includes a plurality of individual message object registers associated with each message object, including at least one control register that contains an interrupt-enable control bit, a receive enable bit, and a transmit enable bit. The CAN microcontroller also includes a plurality of global message object control registers, including at least one message complete status register that contains a plurality of status flag bits for respective ones of the message objects, at least one interrupt flag register that contains a receive complete interrupt flag bit and a transmit complete interrupt flag bit, and a message complete info register that contains a plurality of message object identification bits and a status bit. The CAN/CAL module includes a message handling function that automatically transfers successive frames of an incoming multi-frame message to the message buffer associated with a corresponding message object; an end-of-message detection function that detects an end-of-message condition which occurs when the last frame of the accepted incoming multi-frame message has been stored in the message buffer associated with the corresponding message object; and, an end-of-message detection handling and interrupt generation function that, in response to the detection of the end-of-message condition: sets the status flag bit contained in the at least one message complete status register associated with the corresponding message object; sets the receive complete interrupt flag bit contained in the at least one interrupt flag register, if the interrupt-enable control bit contained in the at least one control register associated with the corresponding message object is set; and, sets the status bit contained in the message complete info register, if the interrupt-enable control bit contained in the at least one control register associated with the corresponding message object is set.

Growing community of inventors

Stamford, CT, United States of America

Richard Fabbri