FreeCalypso > hg > freecalypso-schem2

annotate venus/src/core/xtal_32khz_wrap.v @ 36:c1256c8757c3

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eliminate R209 and tie Iota VLMEM directly to UPR We already eliminated R210 (VLMEM pull-down option) earlier, because our simplified LCD power supply and reset line wiring is incompatible with 1.8V MEMIF. But with VLMEM always needing to be high, a pull-up resistor offers no advantage over a direct tie to UPR, so let's eliminate the superfluous resistor.
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 22 Nov 2021 19:19:59 +0000
parents 3ed0f7a9c489
children
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3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
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1 /*
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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2 * The 32 kHz crystal resonator package used in the TR-800 module
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
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3 * only has the two electrodes as pads, no ground pad.
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
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4 * We shall use the same type of crystal on FC Venus.
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
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5 */
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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7 module xtal_32khz_wrap (electrode1, electrode2, GND);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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9 input electrode1, electrode2, GND;
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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11 xtal_2pin_pkg xtal (electrode1, electrode2);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
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13 endmodule