US 9,813,221 B2
Combined flow and low-power state control using same lines between interfaces
Christophe Arnal, Saint Vallier de Thiey (FR); and Roland Van Der Tuijn, Mouans-Sartoux (FR)
Assigned to STMicroelectronics (Rousset) SAS, Rousset (FR)
Filed by STMICROELECTRONICS (ROUSSET) SAS, Rousset (FR)
Filed on Nov. 3, 2014, as Appl. No. 14/531,442.
Claims priority of application No. 13 61090 (FR), filed on Nov. 13, 2013.
Prior Publication US 2015/0131497 A1, May 14, 2015
Int. Cl. H04B 1/44 (2006.01); H04L 5/14 (2006.01); H04L 12/801 (2013.01); H04W 4/04 (2009.01); G06F 13/42 (2006.01)
CPC H04L 5/1415 (2013.01) [G06F 13/4291 (2013.01); H04L 47/35 (2013.01); H04W 4/04 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method for controlling a low-power state of a pair of serial interfaces using a pair of flow-control signal lines, the method comprising:
enabling a first one of the pair of flow-control signal lines by a first one of the pair of serial interfaces for signal lines a transmission request to a second one of the pair of serial interfaces;
in response to the transmission request, waking up the second one of the pair of serial interfaces to a live state from a low-power state;
enabling a second one of the pair of flow-control signal lines by the second one of the pair of serial interfaces for signal lines a transmission authorization to the first one of the pair of serial interfaces;
in response to the transmission authorization and while keeping enabled the first one of the pair of flow-control signal lines, initiating a transmission of a message by the first one of the pair of serial interfaces to the second one of the pair of serial interfaces;
upon reaching an offset before an end of the transmission of the message, disabling the first one of the pair of flow-control signal lines by the first one of the pair of serial interfaces so that transmissions on the pair of serial interfaces end at a same time, the offset being defined by a smallest data unit whose transmission is not suspended by a flow-control signal;
at the end of the transmission of the message, disabling the second one of the pair of flow-control signal lines by the second one of the pair of serial interfaces and transitioning the second one of the pair of serial interfaces into the low-power state.