FreeCalypso > hg > fc-usbser-tools

comparison cp2102/decode_baudtab.c @ 58:4890ded06a8b

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
cp2102-decode-baudtab program written, compiles
author Mychaela Falconia <falcon@freecalypso.org>
date Mon, 11 Sep 2023 20:33:26 +0000
parents
children 672c7adc8bc9
comparison
equal deleted inserted replaced
57:deba1d5c8024 58:4890ded06a8b
1 /*
2 * The function implemented in this module decodes the baud rate table
3 * contained in the captured CP2102 EEPROM image.
4 */
5
6 #include <sys/types.h>
7 #include <stdio.h>
8 #include <stdlib.h>
9 #include "cp210x_defs.h"
10
11 extern u_char eeprom[SIZE_EEPROM];
12
13 void
14 decode_baud_table(outf)
15 FILE *outf;
16 {
17 unsigned entry;
18 u_char *dp;
19 unsigned baudrate, baudgen, timegen, prescaler, sparebyte;
20 unsigned baud_div, calc_baud, time_us;
21
22 dp = eeprom;
23 for (entry = 0; entry < SIZE_BAUDRATES; entry++) {
24 baudgen = (dp[0] << 8) | dp[1];
25 timegen = (dp[2] << 8) | dp[3];
26 prescaler = dp[4];
27 sparebyte = dp[5];
28 baudrate = dp[6] | (dp[7] << 8) | (dp[8] << 16) | (dp[9] << 24);
29 fprintf(outf, "baud-entry %2u: %7u = %04X, %04X, %u, %u",
30 entry, baudrate, baudgen, timegen, prescaler,
31 sparebyte);
32 if (prescaler) {
33 baud_div = (0x10000 - baudgen) * prescaler;
34 calc_baud = 24000000 / baud_div;
35 fprintf(outf, "\t# %u baud, ", calc_baud);
36 time_us = (0x10000 - timegen) * 2;
37 if (time_us >= 1000)
38 fprintf(outf, "%u.%03u ms", time_us / 1000,
39 time_us % 1000);
40 else
41 fprintf(outf, "%u us", time_us);
42 }
43 putc('\n', outf);
44 }
45 }