HD64F36077GHV Renesas Electronics America, HD64F36077GHV Datasheet - Page 199

• Manufacturer Part Number: HD64F36077GHV
• Description: 16BIT MCU FLASH 56K, SMD, LQFP64
• Manufacturer: Renesas Electronics America

Specifications of HD64F36077GHV

• No. Of I/o's: 47
• Ram Memory Size: 4KB
• Cpu Speed: 20MHz
• No. Of Timers: 4
• Digital Ic Case Style: LQFP
• Supply Voltage Range: 4.5V
• Core Size: 16bit
• Program Memory Size: 56KB
• Oscillator Type: External Only
• Controller Family/series: H8/300H
• Peripherals: ADC
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

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. 1.00 Sep. 16, 2005 Page 169 of 490
Section 10 Realtime Clock (RTC)
REJ09B0216-0100