MC9S08DN60 Datasheet, PDF (252/354 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 14 Real-Time Counter (S08RTCV1)
14.1.4 Block Diagram
The block diagram for the RTC module is shown in Figure 14-2.
LPO
ERCLK
IRCLK
CLOCK
SOURCE
SELECT
BACKGROUND
MODE
RTCLKS
RTCLKS[0]
RTCPS
RTC
PRESCALER _CLOCK
DIVIDE-BY
8-BIT MODULO
(RTCMOD)
V_DD
DQ
8-BIT COMPARATOR
8-BIT COUNTER
(RTCCNT)
E
R
Write 1 to
RTIF
RTIE
RTIF _RTC
INTERRUPT
REQUEST
Figure 14-2. Real-Time Counter (RTC) Block Diagram
14.2 External Signal Description
The RTC does not include any off-chip signals.
14.3 Register Definition
The RTC includes a status and control register, an 8-bit counter register, and an 8-bit modulo register.
Refer to the direct-page register summary in the memory section of this data sheet for the absolute address
assignments for all RTC registers.This section refers to registers and control bits only by their names and
relative address offsets.
Table 14-1 is a summary of RTC registers.
Table 14-1. RTC Register Summary
Name
RTCSC
RTCCNT
RTCMOD
7
6
5
4
3
2
1
0
R
RTIF
W
RTCLKS
RTIE
RTCPS
R
RTCCNT
W
R
RTCMOD
W
MC9S08DN60 Series Data Sheet, Rev 2
252
Freescale Semiconductor