摘要:
An integrated circuit (100) may receive a boot loader code (114) via a debug access port (105), wherein a boot logic is operative to block, upon a reset (123) of the programmable processor (103) from the debug access port (105), commands and to the programmable processor from the debug access port, while still allowing the reset (123) command and while allowing write access to memory (112) to receive the boot loader code image (114) written to memory (112). The boot logic also blocks commands to the memory subsystem (109) from the debug access port and turns off write access to memory (112) after allowing the boot loader code image (114) to be written. The boot logic validates the boot loader code image (114) by performing a security check and jumps to the boot loader code image (114) if it is valid, thereby allowing it to run on the programmable processor (103). The boot logic may be logic circuits, software or a combination thereof.
摘要:
An integrated circuit (100) may receive a boot loader code (114) via a debug access port (105), wherein a boot logic is operative to block, upon a reset (123) of the programmable processor (103) from the debug access port (105), commands and to the programmable processor from the debug access port, while still allowing the reset (123) command and while allowing write access to memory (112) to receive the boot loader code image (114) written to memory (112). The boot logic also blocks commands to the memory subsystem (109) from the debug access port and turns off write access to memory (112) after allowing the boot loader code image (114) to be written. The boot logic validates the boot loader code image (114) by performing a security check and jumps to the boot loader code image (114) if it is valid, thereby allowing it to run on the programmable processor (103). The boot logic may be logic circuits, software or a combination thereof.
摘要:
A method comprising determining that a minimum operation level of an integrated circuit (100) has been reached and that a sleep mode is therefore allowable; storing minimum operation context information to a RAM (115) in response to determining that the minimum operation level has been reached; switching to a sleep mode code (116) in the RAM (115); and transferring memory control from a primary memory controller (104) to a secondary memory controller (112) wherein only the secondary memory controller (112) controls the RAM (115). The method may include storing the sleep mode code (116) and a wakeup code (117) in the RAM (115) in response to determining that sleep mode is allowable, where the wakeup code (117) restores a minimum operation context using the minimum operation context information stored in the RAM (115). The method may also include placing a plurality of integrated circuit power islands into a sleep mode and leaving a secondary memory controller power island (109) in a normal power mode.