tmp19a44fda TOSHIBA Semiconductor CORPORATION, tmp19a44fda Datasheet - Page 496

• Manufacturer Part Number: tmp19a44fda
• Description: 32bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

19.4
Real Time Clock (RTC)
19.4.1 Clock Operation
Operational description
The RTC incorporates a sec. counter that generates an 1Hz signal from a 32.768 KHz signal. The
sec. counter operation must be taken into account when using the RTC.
(1) Reading clock data
1. Using 1Hz interrupt
2. Using pair reading
if reading data after 1Hz interrupt occurred.
operates carry during reading. To ensure correct data reading, read the clock data twice as shown
below. A pair of data read successively needs to match.
The count-up of the internal data synchronizes with 1Hz interrupt. Data can be read correctly
There is a possibility that the clock data may be read incorrectly if the internal counter
Fig. 19.2 Flowchart of the clock data reading
TMP19A44 (rev1.3) 19-10
PAGER<PAGE> = “0”, then
Clock data reading
Clock data reading
select PAGE0
1
st
data = 2
(2nd)
Start
(1st)
End
nd
YES
data
NO
TMP19A44
2010-04-01