diff options
| author | Harald Welte <laforge@gnumonks.org> | 2012-05-18 08:41:08 +0200 |
|---|---|---|
| committer | Harald Welte <laforge@gnumonks.org> | 2012-05-18 08:41:08 +0200 |
| commit | 5aae62cb7b099663d80f83591bd4f6f824fc88fb (patch) | |
| tree | 980a07b25824b34fee7f6776d7f6c916c53cb4c1 /firmware/src/simtrace | |
| parent | f0fb308984a66ca2c6f8fd2a3a2e9edcae1b5ccb (diff) | |
7816_uart: add comment about f/d calculation
Diffstat (limited to 'firmware/src/simtrace')
| -rw-r--r-- | firmware/src/simtrace/iso7816_uart.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/firmware/src/simtrace/iso7816_uart.c b/firmware/src/simtrace/iso7816_uart.c index 4169ab9..5f1bad0 100644 --- a/firmware/src/simtrace/iso7816_uart.c +++ b/firmware/src/simtrace/iso7816_uart.c @@ -157,6 +157,8 @@ static int compute_fidi_ratio(u_int8_t fi, u_int8_t di) if (d == 0) return -EINVAL; + /* See table 7 of ISO 7816-3: From 1000 on we divide by 1/d, + * which equals a multiplication by d */ if (di < 8) ret = f / d; else |