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[/] [open8_urisc/] [trunk/] [VHDL/] [o8_sys_timer.vhd] - Diff between revs 224 and 229
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| Rev 224 |
Rev 229 |
| Line 23... |
Line 23... |
--
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--
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-- VHDL Units : o8_sys_timer
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-- VHDL Units : o8_sys_timer
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-- Description: Provides an 8-bit microsecond resolution timer for generating
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-- Description: Provides an 8-bit microsecond resolution timer for generating
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-- : periodic interrupts for the Open8 CPU.
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-- : periodic interrupts for the Open8 CPU.
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--
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--
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-- Notes : It is possible to set the value to zero, resulting in the
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-- Notes : Setting the output to 0x00 will disable the timer
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-- : output staying high indefinitely. This may cause an issue if
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-- : the output is connected to an interrupt input.
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-- : Also provides uSec_Tick as an output
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--
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--
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-- Revision History
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-- Revision History
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-- Author Date Change
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-- Author Date Change
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------------------ -------- ---------------------------------------------------
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------------------ -------- ---------------------------------------------------
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-- Seth Henry 07/28/11 Design Start
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-- Seth Henry 07/28/11 Design Start
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Line 94... |
if( Wr_En = '1' )then
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if( Wr_En = '1' )then
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Interval <= Wr_Data_q;
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Interval <= Wr_Data_q;
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Update_Interval <= '1';
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Update_Interval <= '1';
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end if;
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end if;
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Rd_Data <= (others => '0');
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Rd_Data <= OPEN8_NULLBUS;
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Rd_En <= Addr_Match and Open8_Bus.Rd_En;
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Rd_En <= Addr_Match and Open8_Bus.Rd_En;
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if( Rd_En = '1' )then
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if( Rd_En = '1' )then
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Rd_Data <= Interval;
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Rd_Data <= Interval;
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end if;
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end if;
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end if;
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end if;
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