WB_MULTIMASTER - Configurable Wishbone Multi-Master
Figure 1. WB_MULTIMASTER - Configurable Wishbone Multi-Master.
The WB_MULTIMASTER peripheral component provides a simple means of sharing a slave Wishbone device between multiple masters.
Similar to, and essentially and extension of the Wishbone Dual Master component, the WB_MULTIMASTER is primarily for use with more than two devices that require access to shared physical memory. For example a processor and two memory-based peripherals, such as a VGA Controller and a BT656 Video Capture Controller. When used to provide dual processor access to a bank of shared peripheral I/O devices, it has an important advantage over the WB_DUALMASTER – its support for passing interrupts from a connected Wishbone Interconnect through to all connected 32-bit processor masters.
The WB_MULTIMASTER component can be used with any of the Wishbone-based processors available in Altium Designer.
Features at-a-glance
- Completely configurable from the schematic sheet
- Facilitates the connection of up to 8 Wishbone Masters
- Ability to control address and data bus widths
- Ability to specify Master accessing mode:
- Round-Robin – giving masters access to the slave in sequence (top to bottom)
- Priority – allowing you to define an order of priority for access to the slave
- Ability to grant one Master instant access to the bus when in 'idle' state
- Supports passing of interrupts from a connected Wishbone Interconnect, through to all connected 32-bit processors (when used to share slave peripheral I/O devices).
Availability
The WB_MULTIMASTER component can be found in the FPGA Peripherals (Wishbone) integrated library (FPGA Peripherals (Wishbone).IntLib), located in the \Library\Fpga folder of the installation.
Designing with the WB_MULTIMASTER
Use the following links to explore use of the WB_MULTIMASTER in more detail: