Functional Description

This VCI target is an hardware locks controller.

VCI-based systems may have some difficulties implementing proper locking of target components as this can be done on buses. As a side-effect, locks and other atomic-access-based software resources can't be used. This component solves this problem implementing the atomic-access-like features on target side.

This components has one bit of information stored on each 32-bit addressable word:

• When read, its current value is returned, and it is implicitly set to 1
• When written to, it is reset to 0.

This way:

• A spin lock is a simple loop waiting to read 0
• Releasing the lock is a simple write operation

CABA Implementations

The caba implementation is in

• source:trunk/soclib/systemc/include/caba/target/vci_locks.h
• source:trunk/soclib/systemc/src/caba/target/vci_locks.cc

Template parameters:

• The VCI parameters

Constructor parameters

• Name
• Target index
• Mapping Table reference

Ports

• p_vci: the VCI port
• p_resetn: Global system reset
• p_clk: Global system clock