| 1 | /* Author : Rick van der Zwet
|
|---|
| 2 | * S-number : 0433373
|
|---|
| 3 | * Version : $Id: memory.h 363 2007-12-03 06:07:31Z rick $
|
|---|
| 4 | * Copyright : FreeBSD Licence
|
|---|
| 5 | * Description : page-mode DRAM with a page-size of PAGESIZE words, a
|
|---|
| 6 | * random access time of RAS clock cycles and a 'next
|
|---|
| 7 | * access time' of NAT clock cycles.
|
|---|
| 8 | */
|
|---|
| 9 |
|
|---|
| 10 | #include <stdio.h>
|
|---|
| 11 | #include <stdlib.h>
|
|---|
| 12 | #include <string.h>
|
|---|
| 13 | #include "common.h"
|
|---|
| 14 |
|
|---|
| 15 | void
|
|---|
| 16 | memory_dram(const int PAGESIZE, const int NAT, const int RAS)
|
|---|
| 17 | {
|
|---|
| 18 | struct bus2_t line;
|
|---|
| 19 | struct result_t output = {0, 0, 0, 0};
|
|---|
| 20 |
|
|---|
| 21 | /* Keep track of which page memory is, cause switching means a lot of
|
|---|
| 22 | * extra work/cycles in terms of empty memory, moving to new bank
|
|---|
| 23 | */
|
|---|
| 24 | int current_page = 0;
|
|---|
| 25 |
|
|---|
| 26 | /* Page location needed by new request */
|
|---|
| 27 | int page_needed = 0;
|
|---|
| 28 |
|
|---|
| 29 | /* Part of page needed by new request */
|
|---|
| 30 | int part_needed = 0;
|
|---|
| 31 |
|
|---|
| 32 | /* Every page has got 64 entries which all can be busy,
|
|---|
| 33 | * by convention 0 means not busy else busy
|
|---|
| 34 | */
|
|---|
| 35 | int * partbusy = (int *)malloc(sizeof(int) * PAGESIZE);
|
|---|
| 36 |
|
|---|
| 37 | int i; /* Temp counter */
|
|---|
| 38 |
|
|---|
| 39 | /* Init all parts to be available in the beginning */
|
|---|
| 40 | memset(partbusy, FALSE, sizeof(int) * PAGESIZE);
|
|---|
| 41 |
|
|---|
| 42 | while (fscanfbus2(&line) != EOF) {
|
|---|
| 43 | /* Process the counts */
|
|---|
| 44 | setstats(&line, &output);
|
|---|
| 45 |
|
|---|
| 46 | /* New request means new cycle as well */
|
|---|
| 47 | output.cycles++;
|
|---|
| 48 |
|
|---|
| 49 | /* Find proper page, do not take advantage of C div operator on
|
|---|
| 50 | * int which is rounding directly, but use more safe/portable
|
|---|
| 51 | * approch */
|
|---|
| 52 | part_needed = line.address % PAGESIZE;
|
|---|
| 53 | page_needed = (line.address - part_needed) / PAGESIZE;
|
|---|
| 54 |
|
|---|
| 55 | /* Determine wether we did hit the right page or not */
|
|---|
| 56 | if (page_needed == current_page) {
|
|---|
| 57 | /* Check whether part is busy, which will result in waiting
|
|---|
| 58 | * till part access is granted
|
|---|
| 59 | */
|
|---|
| 60 | if (partbusy[part_needed] != FALSE) {
|
|---|
| 61 | /* Worst case senario on refresh */
|
|---|
| 62 | output.cycles += RAS;
|
|---|
| 63 | memset(partbusy, FALSE, sizeof(int) * PAGESIZE);
|
|---|
| 64 | }
|
|---|
| 65 | } else {
|
|---|
| 66 | /* Wait till all pending calls in current page are completed
|
|---|
| 67 | * 'Abuse' t to be identifier wether some bank was lowered
|
|---|
| 68 | */
|
|---|
| 69 | /* Worst case senario on refresh */
|
|---|
| 70 | output.cycles += RAS;
|
|---|
| 71 | memset(partbusy, FALSE, sizeof(int) * PAGESIZE);
|
|---|
| 72 |
|
|---|
| 73 | /* Switch to new page */
|
|---|
| 74 | current_page = page_needed;
|
|---|
| 75 | output.cycles += NAT;
|
|---|
| 76 | output.conflicts++;
|
|---|
| 77 | }
|
|---|
| 78 |
|
|---|
| 79 | /* Set new memory access */
|
|---|
| 80 | partbusy[part_needed] = RAS + TRANSFER;
|
|---|
| 81 |
|
|---|
| 82 | /* Process all parts to lower cycle count by one */
|
|---|
| 83 | for (i = 0; i < PAGESIZE; i++) {
|
|---|
| 84 | if (partbusy[i] != FALSE)
|
|---|
| 85 | partbusy[i]--;
|
|---|
| 86 | }
|
|---|
| 87 | }
|
|---|
| 88 |
|
|---|
| 89 | /* Make sure remaining data leaves memory safely */
|
|---|
| 90 |
|
|---|
| 91 | /* Worst case senario on refresh */
|
|---|
| 92 | output.cycles += RAS;
|
|---|
| 93 |
|
|---|
| 94 | /* Delete allocated memory */
|
|---|
| 95 | free(partbusy);
|
|---|
| 96 |
|
|---|
| 97 | printfresult(stdout, &output);
|
|---|
| 98 | }
|
|---|
