Functional Description

This VCI target is a memory mapped peripheral implementing a vectorized interrupt controller. It can concentrate up to 32 independent interrupt lines p_irq_in[i] to a single p_irq interrupt line. The active state is high, and the output interrupt is the logical OR of all input interrupts. Each input interrupt can be individually masked using a memory mapped 32 bits register. This component can be addresse to return the index of the highest priority active interrupt p_irq_[i]. The priority scheme is fixed : The lower indexes have the highest priority. The memory segment allocated to this component must be aligned on 8 bytes boundary. This hardware component cheks for segmentation violation, and can be used as a default target.

This component contains 2 memory mapped registers:

• ICU_INDEX : ADDRESS[2:0] = 0x0

It is actually a 32 bits pseudo-register: A read request returns the index value of the highest priority active input interrupt. If there is no active interrupt, it returns the 32 value. This register is read-only.

• ICU_MASK : ADDRESS[2:0] = 0x4

Each bit i of this 32 bits register enables the corresponding p_irq_in[i] input interrupt, when this bit is one. This register can be read or written.A write request of a zero gives resets this register. This register is write-only.

CABA Implementation

The caba implementation is in

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

Template parameters:

• The VCI parameters

Constructor parameters

VciIcu(
     sc_module_name name,  // Component Name
     const soclib::common::InTab &index, // Target index
     const soclib::common::MappingTable &mt,  // Mapping Table
     size_t nirq);  // Number of input interrupts

Ports

• sc_in<bool> p_resetn : Global system reset
• sc_in<bool> p_clk : Global system clock
• soclib::caba::VciTarget<vci_param> p_vci : VCI port
• sc_out<bool> p_irq : Output interrupt port
• sc_in<bool> *p_irq_in : Pointer to the input interrupts ports table