From 157301faa093f53f069792f89b5b1a0789ef7b95 Mon Sep 17 00:00:00 2001
From: Grzegorz Daniluk <grzegorz.daniluk@cern.ch>
Date: Tue, 10 Sep 2013 10:02:11 +0200
Subject: [PATCH] [switch-optimization]: wb_simple_pwm: add generic to
set/reduce regs size
The values used in WR Switch software fit in 8-bit registers so using 16-bits
in HDL was waste of resources.
---
.../wishbone/wb_simple_pwm/wb_simple_pwm.vhd | 56 ++++++++++++-------
.../wishbone/wb_simple_pwm/xwb_simple_pwm.vhd | 5 +-
modules/wishbone/wishbone_pkg.vhd | 2 +
3 files changed, 41 insertions(+), 22 deletions(-)
diff --git a/modules/wishbone/wb_simple_pwm/wb_simple_pwm.vhd b/modules/wishbone/wb_simple_pwm/wb_simple_pwm.vhd
index 9d434176..d6924d52 100644
--- a/modules/wishbone/wb_simple_pwm/wb_simple_pwm.vhd
+++ b/modules/wishbone/wb_simple_pwm/wb_simple_pwm.vhd
@@ -6,7 +6,7 @@
-- Author : Tomasz Wlostowski
-- Company : CERN BE-Co-HT
-- Created : 2012-12-18
--- Last update: 2012-12-20
+-- Last update: 2013-09-10
-- Platform : FPGA-generic
-- Standard : VHDL'93
-------------------------------------------------------------------------------
@@ -43,6 +43,7 @@ use work.spwm_wbgen2_pkg.all;
entity wb_simple_pwm is
generic(
g_num_channels : integer range 1 to 8;
+ g_regs_size : integer range 1 to 16 := 16;
g_default_period : integer range 0 to 255 := 0;
g_default_presc : integer range 0 to 255 := 0;
g_default_val : integer range 0 to 255 := 0;
@@ -70,16 +71,29 @@ end wb_simple_pwm;
architecture behavioral of wb_simple_pwm is
- type t_drive_array is array(0 to g_num_channels-1) of std_logic_vector(15 downto 0);
+ type t_drive_array is array(0 to g_num_channels-1) of std_logic_vector(g_regs_size-1 downto 0);
procedure f_handle_dr_writes(index : integer; data : std_logic_vector; load : std_logic;
signal d : out t_drive_array) is
begin
if(index <= g_num_channels and load = '1') then
- d(index-1) <= data;
+ d(index-1) <= data(g_regs_size-1 downto 0);
end if;
end f_handle_dr_writes;
+ function f_expand_data(dat : std_logic_vector(g_regs_size-1 downto 0))
+ return std_logic_vector is
+ variable ret : std_logic_vector(15 downto 0);
+ begin
+ if g_regs_size = 16 then
+ ret := dat;
+ else
+ ret(g_regs_size-1 downto 0) := dat;
+ ret(15 downto g_regs_size) := (others=>'0');
+ end if;
+ return ret;
+ end function;
+
component simple_pwm_wb
port (
rst_n_i : in std_logic;
@@ -103,9 +117,9 @@ architecture behavioral of wb_simple_pwm is
signal regs_out : t_spwm_out_registers;
signal tick : std_logic;
- signal cntr_pre, cntr_main : unsigned(15 downto 0);
- signal presc_val : std_logic_vector(15 downto 0);
- signal period_val : std_logic_vector(15 downto 0);
+ signal cntr_pre, cntr_main : unsigned(g_regs_size-1 downto 0);
+ signal presc_val : std_logic_vector(g_regs_size-1 downto 0);
+ signal period_val : std_logic_vector(g_regs_size-1 downto 0);
begin -- behavioral
@@ -130,28 +144,28 @@ begin -- behavioral
-------------------------------------------------------------------------------
p_drive_readback : process(drive)
begin
- regs_in.dr0_i <= drive(0);
+ regs_in.dr0_i <= f_expand_data(drive(0));
if(g_num_channels >= 2) then
- regs_in.dr1_i <= drive(1);
+ regs_in.dr1_i <= f_expand_data(drive(1));
end if;
if(g_num_channels >= 3) then
- regs_in.dr2_i <= drive(2);
+ regs_in.dr2_i <= f_expand_data(drive(2));
end if;
if(g_num_channels >= 4) then
- regs_in.dr3_i <= drive(3);
+ regs_in.dr3_i <= f_expand_data(drive(3));
end if;
if(g_num_channels >= 5) then
- regs_in.dr4_i <= drive(4);
+ regs_in.dr4_i <= f_expand_data(drive(4));
end if;
if(g_num_channels >= 6) then
- regs_in.dr5_i <= drive(5);
+ regs_in.dr5_i <= f_expand_data(drive(5));
end if;
if(g_num_channels >= 7) then
- regs_in.dr6_i <= drive(6);
+ regs_in.dr6_i <= f_expand_data(drive(6));
end if;
if(g_num_channels >= 8) then
- regs_in.dr7_i <= drive(7);
+ regs_in.dr7_i <= f_expand_data(drive(7));
end if;
end process;
@@ -160,7 +174,7 @@ begin -- behavioral
if rising_edge(clk_sys_i) then
if rst_n_i = '0' then
for i in 0 to g_num_channels-1 loop
- drive(i) <= std_logic_vector(to_unsigned(g_default_val, 16));
+ drive(i) <= std_logic_vector(to_unsigned(g_default_val, g_regs_size));
end loop; -- i
else
f_handle_dr_writes(1, regs_out.dr0_o, regs_out.dr0_load_o, drive);
@@ -175,21 +189,21 @@ begin -- behavioral
end if;
end process;
- regs_in.cr_presc_i <= presc_val;
- regs_in.cr_period_i <= period_val;
+ regs_in.cr_presc_i <= f_expand_data(presc_val);
+ regs_in.cr_period_i <= f_expand_data(period_val);
load_cr: process(clk_sys_i)
begin
if rising_edge(clk_sys_i) then
if(rst_n_i = '0') then
- presc_val <= std_logic_vector(to_unsigned(g_default_presc, 16));
+ presc_val <= std_logic_vector(to_unsigned(g_default_presc, g_regs_size));
elsif(regs_out.cr_presc_load_o = '1') then
- presc_val <= regs_out.cr_presc_o;
+ presc_val <= regs_out.cr_presc_o(g_regs_size-1 downto 0);
end if;
if(rst_n_i = '0') then
- period_val <= std_logic_vector(to_unsigned(g_default_period, 16));
+ period_val <= std_logic_vector(to_unsigned(g_default_period, g_regs_size));
elsif(regs_out.cr_period_load_o = '1') then
- period_val <= regs_out.cr_period_o;
+ period_val <= regs_out.cr_period_o(g_regs_size-1 downto 0);
end if;
end if;
end process;
diff --git a/modules/wishbone/wb_simple_pwm/xwb_simple_pwm.vhd b/modules/wishbone/wb_simple_pwm/xwb_simple_pwm.vhd
index cca0d5d7..949839d9 100644
--- a/modules/wishbone/wb_simple_pwm/xwb_simple_pwm.vhd
+++ b/modules/wishbone/wb_simple_pwm/xwb_simple_pwm.vhd
@@ -6,7 +6,7 @@
-- Author : Tomasz Wlostowski
-- Company : CERN BE-Co-HT
-- Created : 2012-12-18
--- Last update: 2012-12-20
+-- Last update: 2013-09-10
-- Platform : FPGA-generic
-- Standard : VHDL'93
-------------------------------------------------------------------------------
@@ -43,6 +43,7 @@ use work.wishbone_pkg.all;
entity xwb_simple_pwm is
generic (
g_num_channels : integer range 1 to 8;
+ g_regs_size : integer range 1 to 16 := 16;
g_default_period : integer range 0 to 255 := 0;
g_default_presc : integer range 0 to 255 := 0;
g_default_val : integer range 0 to 255 := 0;
@@ -66,6 +67,7 @@ architecture wrapper of xwb_simple_pwm is
component wb_simple_pwm
generic (
g_num_channels : integer range 1 to 8;
+ g_regs_size : integer range 1 to 16 := 16;
g_default_period : integer range 0 to 255;
g_default_presc : integer range 0 to 255;
g_default_val : integer range 0 to 255;
@@ -91,6 +93,7 @@ begin -- rtl
U_Wrapped_PWM : wb_simple_pwm
generic map (
g_num_channels => g_num_channels,
+ g_regs_size => g_regs_size,
g_default_period => g_default_period,
g_default_presc => g_default_presc,
g_default_val => g_default_val,
diff --git a/modules/wishbone/wishbone_pkg.vhd b/modules/wishbone/wishbone_pkg.vhd
index 722bfb86..33f22c1b 100644
--- a/modules/wishbone/wishbone_pkg.vhd
+++ b/modules/wishbone/wishbone_pkg.vhd
@@ -754,6 +754,7 @@ package wishbone_pkg is
component wb_simple_pwm
generic (
g_num_channels : integer range 1 to 8;
+ g_regs_size : integer range 1 to 16 := 16;
g_default_period : integer range 0 to 255 := 0;
g_default_presc : integer range 0 to 255 := 0;
g_default_val : integer range 0 to 255 := 0;
@@ -777,6 +778,7 @@ package wishbone_pkg is
component xwb_simple_pwm
generic (
g_num_channels : integer range 1 to 8;
+ g_regs_size : integer range 1 to 16 := 16;
g_default_period : integer range 0 to 255 := 0;
g_default_presc : integer range 0 to 255 := 0;
g_default_val : integer range 0 to 255 := 0;
--
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