DF2148ATE20 Renesas Electronics America, DF2148ATE20 Datasheet - Page 385

• Manufacturer Part Number: DF2148ATE20
• Description: IC H8S MCU FLASH 128K 100-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2100r

Specifications of DF2148ATE20

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: Host Interface, I²C, IrDA, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 74
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 4 V ~ 5.5 V
• Data Converters: A/D 8x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 75°C
• Package / Case: 100-TQFP, 100-VQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -
• Other names: HD64F2148ATE20; HD64F2148ATE20

Switching of Internal Clock and FRC Operation
When the internal clock is changed, the changeover may cause FRC to increment. This depends on
the time at which the clock select bits (CKS1 and CKS0) are rewritten, as shown in table 11.5.
When an internal clock is used, the FRC clock is generated on detection of the falling edge of the
internal clock scaled from the system clock ( ). If the clock is changed when the old source is high
and the new source is low, as in case no. 3 in table 11.5, the changeover is regarded as a falling
edge that triggers the FRC increment clock pulse.
Switching between an internal and external clock can also cause FRC to increment.
Table 11.5 Switching of Internal Clock and FRC Operation
No.
1
2
Timing of Switchover
by Means of CKS1
and CKS0 Bits
Switching from
low to low
Switching from
low to high
FRC Operation
Clock before
switchover
Clock after
switchover
FRC clock
FRC
Clock before
switchover
Clock after
switchover
FRC clock
FRC
N
N
CKS bit rewrite
Rev. 4.00 Sep 27, 2006 page 339 of 1130
Section 11 16-Bit Free-Running Timer
N + 1
CKS bit rewrite
N + 1
REJ09B0327-0400
N + 2