power.h

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/*********************************************************************
 *  The following code is part of the power modelling feature of VTR.
 *
 * For support:
 * http://code.google.com/p/vtr-verilog-to-routing/wiki/Power
 *
 * or email:
 * vtr.power.estimation@gmail.com
 *
 * If you are using power estimation for your researach please cite:
 *
 * Jeffrey Goeders and Steven Wilton.  VersaPower: Power Estimation
 * for Diverse FPGA Architectures.  In International Conference on
 * Field Programmable Technology, 2012.
 *
 ********************************************************************/

/**
 * This is the top-level file for power estimation in VTR
 */

#ifndef __POWER_H__
#define __POWER_H__

/************************* INCLUDES *********************************/
#include <list>

#include "vpr_types.h"
#include "PowerSpicedComponent.h"

/************************* DEFINES ***********************************/
/* Maximum size of logs */
#define MAX_LOGS 10000

/* Default clock behaviour */
#define CLOCK_PROB 0.5
#define CLOCK_DENS 2

/************************* ENUMS ************************************/

/* Return code used by power functions */
typedef enum {
    POWER_RET_CODE_SUCCESS = 0, POWER_RET_CODE_ERRORS, POWER_RET_CODE_WARNINGS
} e_power_ret_code;

/* Power log types */
typedef enum {
    POWER_LOG_ERROR, POWER_LOG_WARNING, POWER_LOG_NUM_TYPES
} e_power_log_type;

/* Multiplexer select encoding types */
#if 0
typedef enum {
    ENCODING_ONE_HOT, /* One SRAM bit per mux input */
    ENCODING_DECODER /* Log2(mux_inputs) SRAM bits */
}e_encoding_type;
#endif

/************************* STRUCTS **********************************/
typedef struct s_power_output t_power_output;
typedef struct s_log t_log;
typedef struct s_power_commonly_used t_power_commonly_used;
typedef struct s_power_mux_volt_inf t_power_mux_volt_inf;
typedef struct s_power_mux_volt_pair t_power_mux_volt_pair;
typedef struct s_power_nmos_leakages t_power_nmos_leakages;
typedef struct s_power_nmos_leakage_pair t_power_nmos_leakage_pair;
typedef struct s_power_buffer_sc_levr_inf t_power_buffer_sc_levr_inf;
typedef struct s_power_tech t_power_tech;
typedef struct s_transistor_inf t_transistor_inf;
typedef struct s_transistor_size_inf t_transistor_size_inf;
typedef struct s_rr_node_power t_rr_node_power;
typedef struct s_power_buffer_size_inf t_power_buffer_size_inf;
typedef struct s_power_buffer_strength_inf t_power_buffer_strength_inf;
typedef struct s_mux_node t_mux_node;
typedef struct s_mux_arch t_mux_arch;
typedef struct s_solution_inf t_solution_inf;
typedef struct s_power_nmos_mux_inf t_power_nmos_mux_inf;
typedef struct s_power_nmos_leakage_inf t_power_nmos_leakage_inf;
typedef struct s_power_mux_info t_power_mux_info;

/* Information on the solution obtained by VPR */
struct s_solution_inf {
    float T_crit;
    int channel_width;
};

/* two types of transisters */
typedef enum {
    NMOS, PMOS
} e_tx_type;

/* Information for a given transistor size */
struct s_transistor_size_inf {
    float size;

    /* Subthreshold leakage, for Vds = Vdd */
    float leakage_subthreshold;

    /* Gate leakage for Vgd/Vgs = Vdd */
    float leakage_gate;

    /* Gate, Source, Drain capacitance */
    float C_g;
    float C_s;
    float C_d;
};

/**
 * Transistor information
 */
struct s_transistor_inf {
    int num_size_entries;
    t_transistor_size_inf * size_inf; /* Array of transistor sizes */
    t_transistor_size_inf * long_trans_inf; /* Long transistor (W=1,L=2) */
};

struct s_power_nmos_mux_inf {
    float nmos_size;
    int max_mux_sl_size;
    t_power_mux_volt_inf * mux_voltage_inf;
};

struct s_power_nmos_leakage_inf {
    float nmos_size;
    int num_leakage_pairs;
    t_power_nmos_leakage_pair * leakage_pairs;
};

/* CMOS technology properties, populated from data in xml file */
struct s_power_tech {
    float PN_ratio; /* Ratio of PMOS to NMOS in inverter */
    float Vdd;

    float tech_size; /* Tech size in nm, for example 90e-9 for 90nm */
    float temperature; /* Temp in C */

    t_transistor_inf NMOS_inf;
    t_transistor_inf PMOS_inf;

    /* Pass Multiplexor Voltage Information */
    int num_nmos_mux_info;
    t_power_nmos_mux_inf * nmos_mux_info;

    /* NMOS Leakage by Vds */
    int num_nmos_leakage_info;
    t_power_nmos_leakage_inf * nmos_leakage_info;

    /* Buffer Info */
    int max_buffer_size;
    t_power_buffer_size_inf * buffer_size_inf;
};

/* Buffer information for a given size (# of stages) */
struct s_power_buffer_size_inf {
    int num_strengths;
    t_power_buffer_strength_inf * strength_inf;
};

/* Set of I/O Voltages for a single-level multiplexer */
struct s_power_mux_volt_inf {
    int num_voltage_pairs;
    t_power_mux_volt_pair * mux_voltage_pairs;
};

/* Single I/O voltage for a single-level multiplexer */
struct s_power_mux_volt_pair {
    float v_in;
    float v_out_min;
    float v_out_max;
};

/* Buffer information for a given buffer stength */
struct s_power_buffer_strength_inf {
    float stage_gain;

    /* Short circuit factor - no level restorer */
    float sc_no_levr;

    /* Short circuit factors - level restorers */
    int num_levr_entries;
    t_power_buffer_sc_levr_inf * sc_levr_inf;
};

/* Buffer short-circuit information for a given input mux size */
struct s_power_buffer_sc_levr_inf {
    int mux_size;

    /* Short circuit factor */
    float sc_levr;
};

/* Vds/Ids subthreshold leakage pair */
struct s_power_nmos_leakage_pair {
    float v_ds;
    float i_ds;
};

/* Output details of the power estimation */
struct s_power_output {
    FILE * out;
    t_log * logs;
    int num_logs;
};

struct s_log {
    char * name;
    char ** messages;
    int num_messages;
};

struct s_power_mux_info {
    /* Mux architecture information for 0..mux_arch_max_size */
    int mux_arch_max_size;
    t_mux_arch * mux_arch;
};

/**
 * Commonly used values that are cached here instead of recalculting each time,
 * also includes statistics.
 */
struct s_power_commonly_used {

    /* Capacitances */
    float NMOS_1X_C_g;
    float NMOS_1X_C_d;
    float NMOS_1X_C_s;

    float PMOS_1X_C_g;
    float PMOS_1X_C_d;
    float PMOS_1X_C_s;

    float INV_1X_C_in;
    float INV_1X_C;
    float INV_2X_C;

    /* Component Callibrations Array [0..POWER_CALLIB_COMPONENT_MAX-1] */
    PowerSpicedComponent ** component_callibration;

    /* Subthreshold leakages */
    float NMOS_1X_st_leakage;
    float NMOS_2X_st_leakage;
    float PMOS_1X_st_leakage;
    float PMOS_2X_st_leakage;

    std::map<float, t_power_mux_info*> mux_info;

    /* Routing stats */
    int max_routing_mux_size;
    int max_IPIN_fanin;
    int max_seg_fanout;
    int max_seg_to_IPIN_fanout;
    int max_seg_to_seg_fanout;

    /* Physical length of a tile (meters) */
    float tile_length;

    /* Size of switch and connection box buffers */
    int num_sb_buffers;
    float total_sb_buffer_size;

    int num_cb_buffers;
    float total_cb_buffer_size;
};

/* 1-to-1 data structure with t_rr_node
 */
struct s_rr_node_power {
    boolean visited; /* When traversing netlist, need to track whether the node has been processed */
    float * in_dens; /* Switching density of inputs */
    float * in_prob; /* Static probability of inputs */
    short num_inputs; /* Number of inputs */
    short selected_input; /* Input index that is selected */
    short driver_switch_type; /* Switch type that drives this resource */
};

/* Architecture information for a multiplexer.
 * This is used to specify transistor sizes, encoding, etc.
 */
struct s_mux_arch {
    int levels;
    int num_inputs;
    float transistor_size;
    //enum e_encoding_type * encoding_types;
    t_mux_node * mux_graph_head;
};

/* A single-level multiplexer data structure.
 * These are combined in a hierarchy to represent
 * multi-level multiplexers
 */
struct s_mux_node {
    int num_inputs; /* Number of inputs */
    t_mux_node * children; /* Multiplexers that drive the inputs [0..num_inputs-1] */
    int starting_pin_idx; /* Applicable to level 0 only, the overall mux primary input index */
    int level; /* Level in the full multilevel mux - 0 = primary inputs to mux */
    boolean level_restorer; /* Whether the output of this mux is level restored */
};

/************************* GLOBALS **********************************/
extern t_solution_inf g_solution_inf;
extern t_power_output * g_power_output;
extern t_power_commonly_used * g_power_commonly_used;
extern t_power_tech * g_power_tech;
extern t_power_arch * g_power_arch;

/************************* FUNCTION DECLARATIONS ********************/

/* Call before using power module */
boolean power_init(char * power_out_filepath,
        char * cmos_tech_behavior_filepath, t_arch * arch,
        t_det_routing_arch * routing_arch);

boolean power_uninit(void);

/* Top-Level Function */
e_power_ret_code power_total(float * run_time_s, t_vpr_setup vpr_setup,
        t_arch * arch, t_det_routing_arch * routing_arch);

#endif /* __POWER_H__ */