5 rtc current time register-mbar + 0x0810, Rtc current time register (0x08 – Freescale Semiconductor MPC5200B User Manual

Page 229

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MPC5200B Users Guide, Rev. 1

7-70

Freescale Semiconductor

Real-Time Clock

7.6.3.5

RTC Current Time Register—MBAR + 0x0810

This is a read-only register.

8:10

Reserved

11:15

Alm_24Hset

Hour setting (in 24 hour format) to be compared to time of day for the purpose of generating
Alarm Status/Interrupt. Can be written at any time.

16:17

Reserved

18:23

Alm_Min_set

Minute setting to be compared to time of day for the purpose of generating Alarm
Status/Interrupt. Can be written at any time.

24:27

Reserved

28

MPEb

Master Periodic Enable bar. Must be written low after reset to allow periodic interrupts.

29

IntEn_day

Enable bit of periodic interrupts at midnight rollover.

30

IntEn_min

Enable bit of periodic interrupts at minute rollover.

31

IntEn_sec

Enable bit of periodic interrupts at second rollover.

Note: The Interrupt enable bits (28, 29, 30, 31) control the Periodic Interrupt coming from the RTC. The separate
Stopwatch/Alarm Interrupt signal does not have a specific interrupt enable bit. An Alarm interrupt is automatically
generated if Alarm is enabled and the Alarm setting matches time of day. Similarly, a Stopwatch expiration, which
shares the Alarm interrupt signal, automatically occurs once the Stopwatch is initiated and the Stopwatch counter
expires.

Table 7-60. RTC Current Time Register

msb 0

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

R

Reserved

Hour

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31 lsb

R

Reserved

Minute

Reserved

Second

W

RESET:

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

0

Bits

Name

Description

0:10

Reserved

11:15

Hour

Hour format can be either 24-hour or 12-hour with AM/PM.

If 24-hour format is selected (SlctHour low in Reg 0), the whole 5-bit hour field designates
current time in 24-hour format.

If 12-hour format is selected (SlctHour high in Reg 0), the MSB of hour field indicates:

• Hour[0]=0: AM,
• Hour[0]=1: PM and
• Hour[1:4] designates current time in 12-hour format.

16:17

Reserved

18:23

Minute

Shows minutes in current time.

Bits

Name

Description

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