Hardware Reference
In-Depth Information
190
SDA <= not i2c_clk;
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nx_state <= slave_addr_rd;
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when slave_addr_rd =>
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SDA <= slave_addr_for_rd(8-i);
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i <= i_reg + 1;
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if i=8 then
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nx_state <= ack5;
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else
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nx_state <= slave_addr_rd;
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end if;
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when ack5 =>
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SDA <= 'Z';
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nx_state <= rd_sec;
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when rd_sec =>
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SDA <= 'Z';
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i <= i_reg + 1;
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if i=8 then
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nx_state <= ack6;
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else
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nx_state <= rd_sec;
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end if;
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when ack6 =>
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SDA <= '0';
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nx_state <= rd_min;
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when rd_min =>
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SDA <= 'Z';
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i <= i_reg + 1;
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if i=8 then
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nx_state <= ack7;
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else
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nx_state <= rd_min;
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end if;
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when ack7 =>
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SDA <= '0';
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nx_state <= rd_hour;
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when rd_hour =>
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SDA <= 'Z';
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i <= i_reg + 1;
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if i=8 then
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nx_state <= no_ack;
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else
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nx_state <= rd_hour;
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end if;
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when no_ack =>
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SDA <= '1';
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nx_state <= stop;
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end case;
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end process;
238
239
--Store data read from RTC and send it to display:
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process (i2c_clk)
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begin
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if rising_edge(i2c_clk) then
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if (pr_state=rd_sec) then
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sec(8-i) <= SDA;
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elsif (pr_state=rd_min) then
