HD64F3684FP Renesas Electronics America, HD64F3684FP Datasheet - Page 185

• Manufacturer Part Number: HD64F3684FP
• Description: IC H8 MCU FLASH 32K 64LQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300H Tinyr

Specifications of HD64F3684FP

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: I²C, SCI
• Peripherals: PWM, WDT
• Number Of I /o: 45
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 64-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

10.4.3
When the seconds, minutes, hours, or day-of-week datum is updated while time data is being read,
the data obtained may not be correct, and so the time data must be read again. Figure 10.4 shows
an example in which correct data is not obtained. In this example, since only RSECDR is read
after data update, about 1-minute inconsistency occurs.
To avoid reading in this timing, the following processing must be performed.
1. Check the setting of the BSY bit, and when the BSY bit changes from 1 to 0, read from the
2. Making use of interrupts, read from the second, minute, hour, and day-of week registers after
3. Read from the second, minute, hour, and day-of week registers twice in a row, and if there is
second, minute, hour, and day-of-week registers. When about 62.5 ms is passed after the BSY
bit is set to 1, the registers are updated, and the BSY bit is cleared to 0.
the IRRTA flag in IRR1 is set to 1 and the BSY bit is confirmed to be 0.
no change in the read data, the read data is used.
Data Reading Procedure
Figure 10.4 Example: Reading of Inaccurate Time Data
Before update
After update
BSY bit = 0
BSY bit -> 1 (under data update)
BSY bit -> 0
(1) Day-of-week data register read
(2) Hour data register read
(3) Minute data register read
(4) Second data register read
RWKDR = H'03, RHDDR = H'13, RMINDR = H'47, RSECDR = H'00
RWKDR = H'03, RHDDR = H'13, RMINDR = H'46, RSECDR = H'59
H'00
H'03
H'13
H'46
Rev.5.00 Nov. 02, 2005 Page 151 of 500
Section 10 Realtime Clock (RTC)
REJ09B0027-0500