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NUC126
Aug. 08, 2018
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Rev 1.03
NUC12
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1. Set SC_RST to low by programming SCRST (SC_
PINCTL[1]) to ‘0’.
2. Set SC_PWR at high level by programming PWREN (SC_PINCTL[0
]) to ‘1’ and SC_DATA at
high level (reception mode) by programming SCDATA (SC_PINCTL[9
]) to ‘1’.
3. Enable SC_CLK clock by programming CLKKEEP (SC_
PINCTL[6]) to ‘1’.
4. De-assert SC_RST to high by programming SCRST (SC_PINCTL[1
]) to ‘1’.
The activation sequence can be controlled in two ways. The procedure is shown as follows:
Software Timing Control:
Set SC_PINCTL and SC_TMRCTLx (x=0, 1, 2) to process the activation sequence. SC_PWR,
SC_CLK, SC_RST and SC_DATA pin state can be programmed by SC_PINCTL. The programming
method is shown in activation sequence. The activation sequence timing can be controlled by setting
SC_TMRCTLx (x=0, 1 ,2). This programming procedure provides user with a flexible timing setting for
activation sequence.
Hardware Timing Control:
Set ACTEN (SC_ALTCTL[3]) to
‘1’ and the interface will perform the activation sequence by hardware.
The SC_PWR to SC_CLK start (T1) and SC_CLK start to SC_RST assert (T2) can be selected by
programming INITSEL (SC_ALTCTL[9:8]). This programming procedure provides user with a simple
setting for activation sequence.
The following describes the activation control sequence in hardware activation mode:
1. Set activation timing by setting INITSEL (SC_ALTCTL[9:8]).
2. Timer0 can be selected by setting TMRSEL (SC_CTL[14:13]) is 11.
3. Set operation mode OPMODE (SC_TMRCTL0[27:24]) to 0011 and give an Answer to Request
(ATR) value by setting CNT (SC_TMRCTL0[23:0]) register.
4. When hardware de-asserts SC_RST to high, hardware will generate an initial end interrupt flag
INITIF (SC_INTSTS[8]) and inform to CPU at the same time if INITIEN (SC_INTEN[8]) is 1. If
the Timer0 decreases the count
er to “0” (started from SC_RST de-assert) and the card does
not response ATR before that time, hardware will generate an interrupt flag TMR0IF
(SC_INTSTS[3]).
Undefined
T1+T1EXT
T2
T3
ATR
SC_PWR
SC_CLK
SC_RST
SC_DATA
INITIF
Note: The values are measured by chip I / O pin and the real value will depend on system design.
Time
T1
T2
T3
Comment
SC_PWR to SC_CLK Start
SC_CLK Start to SC_RST Assert
SC_CLK Start to ART Appear
T1EXT Configurable cycles for T1
00
01
10
11
83.5
133
165
165
491
537
569
42060
T1
Unit: SC Clock
INITSEL
(SC_ALTCTL[9:8])
T2
Figure 6.15-4 SC Activation Sequence