DF2505BR26DV Renesas Electronics America, DF2505BR26DV Datasheet - Page 209

• Manufacturer Part Number: DF2505BR26DV
• Description: IC H8S/2505 MCU FLASH 176-LFBGA
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2500r

Specifications of DF2505BR26DV

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 26MHz
• Connectivity: I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 104
• Program Memory Size: 384KB (384K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 5.5 V
• Data Converters: A/D 16x10b; D/A 2x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 176-LFBGA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Write after Read: If an external write occurs after an external read while the ICIS0 bit in BCRH
is set to 1, an idle cycle is inserted at the start of the write cycle.
Figure 7.28 shows an example of the operation in this case. In this example, bus cycle A is a read
cycle from ROM with a long output floating time, and bus cycle B is a CPU write cycle. In (a), an
idle cycle is not inserted, and a collision occurs in cycle B between the read data from ROM and
the CPU write data. In (b), an idle cycle is inserted, and a data collision is prevented.
Address bus
CS (area A)
CS (area B)
Data bus
HWR
RD
φ
(a) Idle cycle not inserted
(ICIS0 = 0)
T
Bus cycle A
1
Figure 7.28 Example of Idle Cycle Operation (2)
Long output floating time
T
2
T
3
Bus cycle B
T
1
T
2
Data collision
Address bus
CS (area A)
CS (area B)
Data bus
HWR
RD
φ
Rev. 6.00 Sep. 24, 2009 Page 161 of 928
T
1
Bus cycle A
(b) Idle cycle inserted
(Initial value: ICIS0 = 1)
T
2
T
3
Section 7 Bus Controller
T
Bus cycle B
I
T
REJ09B0099-0600
1
T
2