Product data

TDA8007BHL All information provided in this document is subject to legal disclaimers. © NXP B.V. 2012. All rights reserved.
Product data sheet Rev. 9.1 — 18 June 2012 33 of 51
NXP Semiconductors
TDA8007BHL
Multiprotocol IC card interface
8.6 Activation sequence
When the cards are inactive, pins V
CC
, CLK, RST, C4x, C8x and I/O are at low level and
have a low impedance with respect to ground. The step-up converter is stopped.
When everything is satisfactory (voltage supply, card present and no hardware problems),
the system microcontroller may initiate an activation sequence of a present card.
After selecting the card and leaving the UART reset mode, and then configuring the
necessary parameters for the counters and the UART, bit START can be set within
register PCR at t
0
(see Figure 18)
1. The step-up converter is started (t
1
); if one card was already active, then the step-up
converter was already on and nothing more occurs at this step.
2. Pin V
CC
starts rising (t
2
) from 0 V to 3 V or 5 V with a controlled rise time of 0.17 V/µs
(typical).
3. Pin I/O rises to V
CC
(t
3
); pins C4x and C8x also rise if bits C4 and C8 within
register PCR have been set to logic 1 (integrated 14 k pull-up resistors to V
CC
).
4. Clock pulse CLK is sent to the card (t
4
) and pin RST is enabled.
5. After a number of CLK pulses that can be counted with the time-out counter,
bit RSTIN may be set by software and pin RST will then rise to V
CC
.
6. The sequencer is clocked by
1
⁄
64
f
int
which leads to a time interval of t = 25 µs (typical).
Thus:
t
1
=0to
1
⁄
64
t
t
2
=t
1
+
3
⁄
2
t
t
3
=t
1
+
7
⁄
2
t
4
=t
1
+4t.
Fig 18. Activation sequence
START
V
UP
V
CC
I/O
RSTIN
CLK
RST
t
0
t
2
t
3
t
4
= t
act
ATR
t
1
fce684