Datasheet

PN512 All information provided in this document is subject to legal disclaimers. © NXP Semiconductors N.V. 2016. All rights reserved.
Product data sheet
COMPANY PUBLIC
Rev. 5.2 — 16 June 2016
111352 58 of 137
NXP Semiconductors
PN512
Full NFC Forum-compliant frontend
6 to 5 TGated The internal timer is running in gated mode.
Note: In the gated mode, the bit TRunning is 1 when the timer is enabled
by the register bits. This bit does not influence the gating signal.
Value Description
00 Non gated mode
01 Gated by SIGIN
10 Gated by AUX1
11 Gated by A3
4 TAutoRestart Set to logic 1, the timer automatically restart its count-down from
TReloadValue, instead of counting down to zero.
Set to logic 0 the timer decrements to ZERO and the bit TimerIRq is set
to logic 1.
3 to 0 TPrescaler_Hi Defines higher 4 bits for TPrescaler.
The following formula is used to calculate f
Timer
if TPrescalEven bit in
Demot Reg is set to logic 0:
f
Timer
= 13.56 MHz/(2*TPreScaler+1).
Where TPreScaler = [TPrescaler_Hi:TPrescaler_Lo] (TPrescaler value
on 12 bits) (Default TPrescalEven is logic 0)
The following formula is used to calculate fTimer if TPrescalEven bit in
Demot Reg is set to logic 1:
f
Timer
= 13.56 MHz/(2*TPreScaler+2).
For detailed description see Section 14 “
Timer unit”. For the behaviour
within version 1.0, see Section 20 “
Errata sheet” on page 109.
Table 101. TPrescalerReg register (address 2Bh); reset value: 00h, 00000000b
7 6 5 4 3 2 1 0
TPrescaler_Lo
Access
Rights
r/w r/w r/w r/w r/w r/w r/w r/w
Table 102. Description of TPrescalerReg bits
Bit Symbol Description
7 to 0 TPrescaler_Lo Defines lower 8 bits for TPrescaler.
The following formula is used to calculate f
Timer
if TPrescalEven bit in
Demot Reg is set to logic 0:
f
Timer
= 13.56 MHz/(2*TPreScaler+1).
Where TPreScaler = [TPrescaler_Hi:TPrescaler_Lo] (TPrescaler value
on 12 bits)
The following formula is used to calculate fTimer if TPrescalEven bit in
Demot Reg is set to logic 1:
f
Timer
= 13.56 MHz/(2*TPreScaler+2).
Where TPreScaler = [TPrescaler_Hi:TPrescaler_Lo] (TPrescaler value
on 12 bits)
For detailed description see Section 14 “
Timer unit”.
Table 100. Description of TModeReg bits …continued
Bit Symbol Description