Invention Grant
- Patent Title: Hardware based XIP exit sequence to enable XIP mode operation on SPI boot interface
-
Application No.: US14861451Application Date: 2015-09-22
-
Publication No.: US09910676B1Publication Date: 2018-03-06
- Inventor: Unnikrishnan Sivaraman Nair , Sujaata Ramalingam
- Applicant: Microsemi Solutions (U.S.), Inc.
- Applicant Address: US CA Aliso Viejo
- Assignee: MICROSEMI SOLUTIONS (U.S.), INC.
- Current Assignee: MICROSEMI SOLUTIONS (U.S.), INC.
- Current Assignee Address: US CA Aliso Viejo
- Agency: Leber IP Law
- Agent Dennis R. Haszko
- Main IPC: G06F3/00
- IPC: G06F3/00 ; G06F13/00 ; G06F5/00 ; G06F13/28 ; G06F9/44 ; G06F13/42 ; G06F1/24 ; G06F1/08

Abstract:
Methods and apparatus are provided for controlling one or more memory devices connected to an input output (IO) circuit through a serial peripheral interface (SPI), to make any device which is in execute in place (XIP) mode exit XIP mode. An example method comprises driving an initial signal from the IO circuit onto the data pins for a first plurality of clock cycles, the initial signal causing any memory device not in XIP mode to treat subsequent signals as a dummy read, disabling a driving function of the IO circuit prior to a negative edge of a last one of the first plurality of clock cycles, stopping generation of clock signals for a transition waiting period after the first plurality of clock cycles, and activating a weak pull-up of the IO circuit to apply logic high on all of the data pins for a second plurality of clock cycles.
Information query