DF2378BVFQ35WV Renesas Electronics America, DF2378BVFQ35WV Datasheet - Page 338

• Manufacturer Part Number: DF2378BVFQ35WV
• Description: IC H8S/2378 MCU FLASH 144-QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2300r

Specifications of DF2378BVFQ35WV

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 35MHz
• Connectivity: I²C, IrDA, SCI, SmartCard
• Peripherals: DMA, POR, PWM, WDT
• Number Of I /o: 97
• Program Memory Size: 512KB (512K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 V
• Data Converters: A/D 16x10b; D/A 6x8b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 144-QFP
• For Use With: EDK2378 - DEV EVAL KIT FOR H8S/2378
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

Section 6 Bus Controller (BSC)
6.11.1
In externally expanded mode, the bus can be released to an external device by setting the BRLE
bit to 1 in BCR. Driving the BREQ pin low issues an external bus request to this LSI. When the
BREQ pin is sampled, at the prescribed timing the BACK pin is driven low, and the address bus,
data bus, and bus control signals are placed in the high-impedance state, establishing the external
bus released state.
In the external bus released state, internal bus masters except the EXDMAC can perform accesses
using the internal bus. When an internal bus master wants to make an external access, it
temporarily defers initiation of the bus cycle, and waits for the bus request from the external bus
master to be canceled. If a refresh request is generated in the external bus released state, or if a
SLEEP instruction is executed to place the chip in software standby mode or all-module-clocks-
stopped mode, refresh control and software standby or all-module-clocks-stopped control is
deferred until the bus request from the external bus master is canceled.
If the BREQOE bit is set to 1 in BCR, the BREQO pin can be driven low when any of the
following requests are issued, to request cancellation of the bus request externally.
• When an internal bus master wants to perform an external access
• When a refresh request is generated
• When a SLEEP instruction is executed to place the chip in software standby mode or all-
When the BREQ pin is driven high, the BACK pin is driven high at the prescribed timing and the
external bus released state is terminated.
If an external bus release request and external access occur simultaneously, the order of priority is
as follows:
If a refresh request and external bus release request occur simultaneously, the order of priority is
as follows:
Rev.7.00 Mar. 18, 2009 page 270 of 1136
REJ09B0109-0700
module-clocks-stopped mode
(High) External bus release > External access by internal bus master (Low)
(High) Refresh > External bus release (Low)
Operation