FreeCalypso > hg > freecalypso-schem2

annotate venus/src/core/int_vcxo_passive.v @ 81:fbe54d6cd082

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
capture initial population of RLC67[0-5]
author Mychaela Falconia <falcon@freecalypso.org>
date Sun, 05 Dec 2021 04:41:45 +0000
parents d0b6c4915397
children
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
9
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
1 /*
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
2 * This module captures the mysterious all-passive circuit between Iota's
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
3 * AFC output and Rita's XIN input as depicted on the Leonardo schematics.
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
4 * This circuit defies understanding, but it appears in Openmoko's GSM
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
5 * modem (unchanged from Leonardo) and that modem works, hence we deem
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
6 * this voodoo circuit to be suitable for mindless copying w/o understanding...
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
7 *
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
8 * Note that C205 is not included here, as it's already been included
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
9 * in the abb_block wrapper instead.
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
10 */
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
11
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
12 module int_vcxo_passive (AFC_in, XIN_connection, GND);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
13
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
14 input AFC_in, GND;
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
15 inout XIN_connection;
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
16
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
17 wire R217_to_xtal, xtal_to_R211, R211_to_C225;
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
18
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
19 resistor R217 (AFC_in, R217_to_xtal);
31
d0b6c4915397 Venus MCL: use new ipc-diode.pinout, add SS34 for charging
Mychaela Falconia <falcon@freecalypso.org>
parents: 9
diff changeset
20 varactor_diode D200 (.C(R217_to_xtal), .A(GND));
9
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
21 capacitor C226 (R217_to_xtal, GND);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
22 xtal_4pin_pkg xtal (.pin_1(xtal_to_R211), .pin_2(GND),
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
23 .pin_3(R217_to_xtal), .pin_4(GND));
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
24 resistor R211 (xtal_to_R211, R211_to_C225);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
25 capacitor C224 (R211_to_C225, GND);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
26 capacitor C225 (R211_to_C225, XIN_connection);
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
27
3ed0f7a9c489 Venus: first version of Verilog for the Calypso core
Mychaela Falconia <falcon@freecalypso.org>
parents:
diff changeset
28 endmodule