TMP91C824
91C824-15
2008-02-20
3.3.2 SFR
7 6 5 4 3 2 1 0
SYSCR0
Bit symbol
XEN XTEN RXEN
RXTEN
RSYSCK
WUEF
PRCK1
PRCK0
(00E0H)
Read/Write R/W
After reset
1 1 1 0 0 0 0 0
Function
High-
frequency
oscillator (fc)
0: Stop
1: Oscillation
Low-
frequency
oscillator (fs)
0: Stop
1: Oscillation
(Note 1)
High-
frequency
oscillator (fc)
after release
of STOP
mode
0: Stop
1: Oscillation
Low-
frequency
oscillator (fs)
after release
of STOP
mode
0: Stop
1: Oscillation
Selects clock
after release
of STOP
mode
0: fc
1: fs
Warm-up timer
0: Write
Don’t
care
1: Write
start
timer
0: Read
end warm up
1: Read
do not end
warm
up
Select prescaler clock
00: fFPH (Note 2)
01: Reserved
10: fc/16
11: Reserved
7 6 5 4 3 2 1 0
SYSCR1
Bit symbol
SYSCK GEAR2 GEAR1 GEAR0
(00E1H)
Read/Write
R/W
After reset
0 1 0 0
Function
Select
system
clock
0: fc
1: fs
Select gear value of high frequency (fc)
000: fc
001: fc/2
010: fc/4
011: fc/8
100: fc/16
101: (Reserved)
110: (Reserved)
111: (Reserved)
7 6 5 4 3 2 1 0
SYSCR2
Bit symbol
SCOSEL WUPTM1
WUPTM0
HALTM1
HALTM0 SELDRV DRVE
(00E2H)
Read/Write
R/W R/W R/W R/W R/W R/W R/W
After reset
0 1 0 1 1 0 0
Function
0: fs
1: f
SYS
Warm-up timer
00: Reserved
01: 2
8
inputted frequency
10: 2
14
11: 2
16
HALT mode
00: Reserved
01: STOP mode
10: IDLE1 mode
11: IDLE2 mode
<DRVE>
mode
select
0: STOP
1: IDLE1
Pin state
control in
STOP/IDLE1
mode
0: I/O off
1: Remains
the state
before
halt
Note 1: By reset, low-frequency oscillator is enable.
Note 2: In case of using built-in SBI circuit, it must set SYSCR0<PRCK1:0> to 00.
Figure 3.3.3 SFR for System Clock