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Diffstat (limited to 'control_lib/pic.v')
| -rw-r--r-- | control_lib/pic.v | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/control_lib/pic.v b/control_lib/pic.v deleted file mode 100644 index 9b9944d4a..000000000 --- a/control_lib/pic.v +++ /dev/null @@ -1,183 +0,0 @@ - -// Heavily modified by M. Ettus, 2009, little original code remains -// Modified by M. Ettus, 2008 for 32 bit width - -///////////////////////////////////////////////////////////////////// -//// //// -//// OpenCores Simple Programmable Interrupt Controller //// -//// //// -//// Author: Richard Herveille //// -//// richard@asics.ws //// -//// www.asics.ws //// -//// //// -///////////////////////////////////////////////////////////////////// -//// //// -//// Copyright (C) 2002 Richard Herveille //// -//// richard@asics.ws //// -//// //// -//// This source file may be used and distributed without //// -//// restriction provided that this copyright statement is not //// -//// removed from the file and that any derivative work contains //// -//// the original copyright notice and the associated disclaimer.//// -//// //// -//// THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY //// -//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED //// -//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS //// -//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR //// -//// OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, //// -//// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES //// -//// (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE //// -//// GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR //// -//// BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF //// -//// LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT //// -//// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT //// -//// OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE //// -//// POSSIBILITY OF SUCH DAMAGE. //// -//// //// -///////////////////////////////////////////////////////////////////// -// -// This is a simple Programmable Interrupt Controller. -// The number of interrupts is depending on the databus size. -// There's one interrupt input per databit (i.e. 16 interrupts for a 16 -// bit databus). -// All attached devices share the same CPU priority level. -// -// -// -// Registers: -// -// 0x00: EdgeEnable Register -// bits 7:0 R/W Edge Enable '1' = edge triggered interrupt source -// '0' = level triggered interrupt source -// 0x01: PolarityRegister -// bits 7:0 R/W Polarity '1' = high level / rising edge -// '0' = low level / falling edge -// 0x02: MaskRegister -// bits 7:0 R/W Mask '1' = interrupt masked (disabled) -// '0' = interrupt not masked (enabled) -// 0x03: PendingRegister -// bits 7:0 R/W Pending '1' = interrupt pending -// '0' = no interrupt pending -// -// A CPU interrupt is generated when an interrupt is pending and its -// MASK bit is cleared. -// -// -// -// HOWTO: -// -// Clearing pending interrupts: -// Writing a '1' to a bit in the interrupt pending register clears the -// interrupt. Make sure to clear the interrupt at the source before -// writing to the interrupt pending register. Otherwise the interrupt -// will be set again. -// -// Priority based interrupts: -// Upon reception of an interrupt, check the interrupt register and -// determine the highest priority interrupt. Mask all interrupts from the -// current level to the lowest level. This negates the interrupt line, and -// makes sure only interrupts with a higher level are triggered. After -// completion of the interrupt service routine, clear the interrupt source, -// the interrupt bit in the pending register, and restore the MASK register -// to it's previous state. -// -// Addapt the core for fewer interrupt sources: -// If less than 8 interrupt sources are required, than the 'is' parameter -// can be set to the amount of required interrupts. Interrupts are mapped -// starting at the LSBs. So only the 'is' LSBs per register are valid. All -// other bits (i.e. the 8-'is' MSBs) are set to zero '0'. -// Codesize is approximately linear to the amount of interrupts. I.e. using -// 4 instead of 8 interrupt sources reduces the size by approx. half. -// - - -module pic - (input clk_i, input rst_i, input cyc_i, input stb_i, - input [2:0] adr_i, - input we_i, - input [31:0] dat_i, - output reg [31:0] dat_o, - output reg ack_o, - output reg int_o, - input [31:0] irq - ); - - reg [31:0] pol, edgen, pending, mask; // register bank - reg [31:0] lirq, dirq; // latched irqs, delayed latched irqs - - // latch interrupt inputs - always @(posedge clk_i) - lirq <= irq; - - // generate delayed latched irqs - always @(posedge clk_i) - dirq <= lirq; - - // generate actual triggers - function trigger; - input edgen, pol, lirq, dirq; - reg edge_irq, level_irq; - begin - edge_irq = pol ? (lirq & ~dirq) : (dirq & ~lirq); - level_irq = pol ? lirq : ~lirq; - trigger = edgen ? edge_irq : level_irq; - end - endfunction - - reg [31:0] irq_event; - integer n; - always @(posedge clk_i) - for(n = 0; n < 32; n = n+1) - irq_event[n] <= trigger(edgen[n], pol[n], lirq[n], dirq[n]); - - // generate wishbone register bank writes - wire wb_acc = cyc_i & stb_i; // WISHBONE access - wire wb_wr = wb_acc & we_i; // WISHBONE write access - - always @(posedge clk_i) - if (rst_i) - begin - pol <= 0; // clear polarity register - edgen <= 0; // clear edge enable register - mask <= 0; // mask all interrupts - end - else if(wb_wr) // wishbone write cycle?? - case (adr_i) // synopsys full_case parallel_case - 3'd0 : edgen <= dat_i; // EDGE-ENABLE register - 3'd1 : pol <= dat_i; // POLARITY register - 3'd2 : mask <= dat_i; // MASK register - 3'd3 : ; // PENDING register is a special case (see below) - 3'd4 : ; // Priority encoded live (pending & ~mask) - endcase - - // pending register is a special case - always @(posedge clk_i) - if (rst_i) - pending <= 0; // clear all pending interrupts - else if ( wb_wr & (adr_i == 3'd3) ) - pending <= (pending & ~dat_i) | irq_event; - else - pending <= pending | irq_event; - - wire [31:0] live_enc; - priority_enc priority_enc ( .in(pending & ~mask), .out(live_enc) ); - - always @(posedge clk_i) - case (adr_i) // synopsys full_case parallel_case - 3'd0 : dat_o <= edgen; - 3'd1 : dat_o <= pol; - 3'd2 : dat_o <= mask; - 3'd3 : dat_o <= pending; - 3'd4 : dat_o <= live_enc; - endcase - - always @(posedge clk_i) - ack_o <= wb_acc & !ack_o; - - always @(posedge clk_i) - if(rst_i) - int_o <= 0; - else - int_o <= |(pending & ~mask); - -endmodule |