Method and apparatus to enable multiple masters to operate in a single master bus architecture
First Claim
Patent Images
1. A method operational on a first master device, comprising:
- managing communications over a data bus for a plurality of devices coupled to the data bus, wherein two or more master devices are coupled to the data bus;
determining when an in-band interrupt request has been asserted on the data bus;
determining whether the in-band interrupt request on the data bus was asserted by a second master device; and
handing over control of the data bus to the second master device after determining that the second master device asserted the in-band interrupt request.
1 Assignment
0 Petitions
Accused Products
Abstract
To accommodate multiple masters over bus architectures supporting a single master device, a mechanism is provided for an inactive master device to assert an in-band IRQ. A current master then polls the other inactive master devices over a shared data bus to ascertain which inactive master device is asserting the IRQ. Upon identifying the asserting inactive master device, the current master device grants control of the data bus to the new master device, thereby making the inactive master the new active master device.
-
Citations
30 Claims
-
1. A method operational on a first master device, comprising:
-
managing communications over a data bus for a plurality of devices coupled to the data bus, wherein two or more master devices are coupled to the data bus; determining when an in-band interrupt request has been asserted on the data bus; determining whether the in-band interrupt request on the data bus was asserted by a second master device; and handing over control of the data bus to the second master device after determining that the second master device asserted the in-band interrupt request. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A method operational on a first master device coupled to a data bus, comprising:
-
asserting an in-band interrupt request through the data bus while the data bus is controlled by a second master device; determining whether the second master device has released control of the data bus after assertion of the in-band interrupt request; and acquiring control of the data bus when the second master device has released control of the data bus. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. An apparatus comprising:
-
a serial data bus having a first wire and a second wire, the first wire being coupled to a pull-up or pull-down resistor; and a plurality of devices coupled to the serial data bus, including a first master device and a second master device, wherein the first master device is configured to; manage communications over the serial data bus for the plurality of devices coupled to the serial data bus; drive the first wire to a first signaling state; release control of the first wire, wherein the first wire is initially held in the first signaling state by the pull-up or pull-down resistor; and determine that an in-band interrupt request on the serial data bus was asserted when the first wire is driven to a second signaling state, and wherein the second master device is configured to; determine that a period of time when the first master device is receptive to interrupts has commenced; assert the in-band interrupt request by driving the first wire of the serial data bus to the second signaling state during the period of time when the first master device is receptive to interrupts; and release the first wire of the serial data bus prior to expiration of the period of time when the first master device is receptive to interrupts. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27)
-
-
28. An apparatus comprising:
-
means for managing communications over a multi-wire bus for a plurality of devices coupled to the multi-wire bus, wherein two or more master devices are coupled to the multi-wire bus; means for providing interrupt opportunities for the plurality of devices; means for determining when an in-band interrupt request has been asserted during an interrupt opportunity; and means for identifying a source of in-band interrupt requests asserted on the multi-wire bus. - View Dependent Claims (29, 30)
-
Specification