CLRC663 Datasheet, PDF (83/132 Pages) NXP Semiconductors – Contactless reader IC

NXP Semiconductors
CLRC663
Contactless reader IC
Table 118. T4Control bits
Bit
Symbol
Description
7
T4Running
Shows if the timer T4 is running. If the bit T4StartStopNow is set, this
bit and the timer T4 can be started/stopped.
6
T4Start
if set, the bit T4Running can be changed
StopNow
5
T4AutoTrimm If set to one, the timer activates an LPO trimming procedure when it
underflows. For the T4AutoTrimm function, at least one timer (T0 to
T3) has to be configured properly for trimming (T3 is not allowed if
T4AutoLPCD is set in parallel).
4
T4AutoLPCD If set to one, the timer activates a low-power card detection
sequence. If a card is detected an interrupt request is raised and the
system remains active if enabled. If no card is detected the CLRC663
enters the Power down mode if enabled. The timer is automatically
restarted (no gap). Timer 3 is used to specify the time where the RF
field is enabled to check if a card is present. Therefor you may not
use Timer 3 for T4AutoTrimm in parallel.
3
T4AutoRestart Set to logic 1, the timer automatically restarts its countdown from
T4ReloadValue, after the counter value has reached the value zero.
Set to logic 0 the timer decrements to zero and stops. The bit
Timer4Irq is set to logic 1 at timer underflow.
2
T4AutoWakeUp If set, the CLRC663 wakes up automatically, when the timer T4 has
an underflow. This bit has to be set if the IC should enter the Power
down mode after T4AutoTrimm and/or T4AutoLPCD is finished and
no card has been detected. If the IC should stay active after one of
these procedures this bit has to be set to 0.
1 to 0 T4Clk
00b - the timer input clock is the LFO clock
01b - the timer input clock is the LFO clock/8
10b - the timer input clock is the LFO clock/16
11b - the timer input clock is the LFO clock/32
9.7.2.21 T4ReloadHi
High byte of the reload value of the 16-bit timer 4.
Table 119. T4ReloadHi register (address 24h)
Bit
7
6
5
Symbol
Access
rights
4
3
T4ReloadHi
r/w
2
1
0
Table 120. T4ReloadHi bits
Bit
Symbol
Description
7 to 0
T4ReloadHi
Defines high byte of the for the reload value of timer 4. With the start
event the timer 4 loads the T4ReloadVal. Changing this register affects
the timer only at the next start event
9.7.2.22 T4ReloadLo
Low byte of the reload value of the 16-bit timer 4.
CLRC663
Product data sheet
COMPANY PUBLIC
All information provided in this document is subject to legal disclaimers.
Rev. 3.3 — 3 April 2012
171133
© NXP B.V. 2012. All rights reserved.
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