NO:
W90P710 Programming Guide
VERSION:
2.0
PAGE:
195
The above information is the exclusive intellectual property of Winbond Electronics and shall not be disclosed, distributed or reproduced without permission
from Winbond.
Table No.: 2005-W90P710-11-A
4. Mode 3 (3b’011):Timer starts counting the content of register
SCHI_TOIR
on the first START
bit (reception or transmission) detected on the pin I/O after 3b’010 is written in register
SCHI_TOC
. When timer reaches its terminal count, an interrupt is given if enable, and time-
out flag bit of register
SCHI_SCSR
will be set. The timer is stopped by writing 3b’000 in
register
SCHI_TOC
.
5. Mode 4 (3b’100): Same as Mode 0, except that timer will be stopped at the end of the 12
th
ETU following the first START bit detected after 3b’100 has been written in register
SCHI_TOC
.
Note:
(1) The count unit of all timers is 1 ETU.
(2) Need at least 1 ETU delay during mode translation (eg. change Mode 1,2 or 3 to Mode 0).
(3) Writing the same mode value to
SCHI_TOC
can’t trigger the same timer again, so must
change to Mode 0 before triggering the same mode.
(4) Current bug: when reading register
SCHI_SCSR
, time-out flag can’t be clean, if user
does not enable timer interrupt in register
SCHI_IER
.
Examples of using these timers are given below.
16.3.2.1 ATR
In case of a cold reset, after having applied CLK, the reader has to maintain RST in low state for
a period of between 40000 and 45000 clock cycles before set RST in high state.
1. Load
register
SCHI_TOIR0
with 0x6c. (40000
≤
0x6c * 372
≤
45000)
2. Configure TCO [2~0] in register SCHI_TCO with 3b’001.
3. Clear
bit
PWRDN
of register
SCHI_IER
.
4. Wait for interrupt of
TO0
in register
SCHI_SCSR
.
5. Set
SC_REST
of register
SCHI_SCSR
.
Then the answer to reset from the card should begin between 400 and 40000 clock cycles. That
means that the time between timer start counting and the leading edge of the start bit of the first
received character should not exceed 108 ETU. (40000 < 108 * 372 = 40176). If first character of ATR
has not been received before 120 ETU (include first received character transmitting time: 12 ETU), the
card can be considered as mute.
