MC9S08DZ16 FREESCALE [Freescale Semiconductor, Inc], MC9S08DZ16 Datasheet - Page 313

• Manufacturer Part Number: MC9S08DZ16
• Description: 8-Bit HCS08 Central Processor Unit (CPU)
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

15.3.1
RTCSC contains the real-time interrupt status flag (RTIF), the clock select bits (RTCLKS), the real-time
interrupt enable bit (RTIE), and the prescaler select bits (RTCPS).
Freescale Semiconductor
RTCLKS[0]
RTCLKS
RTCPS
Field
RTIE
RTIF
6–5
3–0
0
1
7
4
Reset:
W
R
RTC Status and Control Register (RTCSC)
Real-Time Interrupt Flag This status bit indicates the RTC counter register reached the value in the RTC modulo
register. Writing a logic 0 has no effect. Writing a logic 1 clears the bit and the real-time interrupt request. Reset
clears RTIF.
0 RTC counter has not reached the value in the RTC modulo register.
1 RTC counter has reached the value in the RTC modulo register.
Real-Time Clock Source Select. These two read/write bits select the clock source input to the RTC prescaler.
Changing the clock source clears the prescaler and RTCCNT counters. When selecting a clock source, ensure
that the clock source is properly enabled (if applicable) to ensure correct operation of the RTC. Reset clears
RTCLKS.
00 Real-time clock source is the 1-kHz low power oscillator (LPO)
01 Real-time clock source is the external clock (ERCLK)
1x Real-time clock source is the internal clock (IRCLK)
Real-Time Interrupt Enable. This read/write bit enables real-time interrupts. If RTIE is set, then an interrupt is
generated when RTIF is set. Reset clears RTIE.
0 Real-time interrupt requests are disabled. Use software polling.
1 Real-time interrupt requests are enabled.
Real-Time Clock Prescaler Select. These four read/write bits select binary-based or decimal-based divide-by
values for the clock source. See
counters. Reset clears RTCPS.
Off
Off
0
RTIF
7
0
2
2
1
10
3
2
2
2
11
Figure 15-3. RTC Status and Control Register (RTCSC)
5
2
0
2
6
3
12
6
Table 15-3. RTC Prescaler Divide-by values
RTCLKS
Table 15-2. RTCSC Field Descriptions
MC9S08DZ60 Series Data Sheet, Rev. 4
2
2
4
13
7
Table
2
0
5
2
5
14
8
15-3. Changing the prescaler value clears the prescaler and RTCCNT
2
2
6
15
9
RTIE
2
2
0
4
7
10
16
Description
RTCPS
10
8
1
3
2x10
0
3
9
2
3
5x10
10
2
2
Chapter 15 Real-Time Counter (S08RTCV1)
3
0
2
10
11
10
RTCPS
4
2x10
12
2
4
4
0
1
5x10
10
13
2
4
5x10
10
14
5
0
0
2
2x10
10
15
313
3
5