DF2556FC20DV Renesas Electronics America, DF2556FC20DV Datasheet - Page 205

• Manufacturer Part Number: DF2556FC20DV
• Description: IC H8S/2556 MCU FLASH 144QFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8S/2500r

Specifications of DF2556FC20DV

• Core Processor: H8S/2000
• Core Size: 16-Bit
• Speed: 20MHz
• Connectivity: CAN, I²C, SCI
• Peripherals: POR, PWM, WDT
• Number Of I /o: 104
• Program Memory Size: 512KB (512K 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: 144-QFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

7.7
With this LSI, external address space of area 0 can be designated as burst ROM space, and burst
ROM interfacing can be performed. The burst ROM space interface enables 16-bit configuration
ROM with burst access capability to be accessed at high speed.
Area 0 can be designated as burst ROM space by means of the BRSTRM bit in BCRH.
Consecutive burst accesses of a maximum of 4 words or 8 words can be performed for CPU
instruction fetches only. One or two states can be selected for burst access.
7.7.1
The number of access states in the initial cycle (full access) of the burst ROM interface is in
accordance with the setting of the AST0 bit in ASTCR. Also, when the AST0 bit is set to 1, wait
states can be inserted. One or two states can be selected for the burst cycle, according to the
setting of the BRSTS1 bit in BCRH. Wait states cannot be inserted. When area 0 is designated as
burst ROM space, it becomes 16-bit access space regardless of the setting of the ABW0 bit in
ABWCR.
When the BRSTS0 bit in BCRH is cleared to 0, burst access of up to 4 words is performed; when
the BRSTS0 bit is set to 1, burst access of up to 8 words is performed.
The basic access timing for burst ROM space is shown in figures 7.25 and 7.26. The timing shown
in figure 7.25 is for the case where the AST0 and BRSTS1 bits are both set to 1, and that in figure
7.26 is for the case where both these bits are cleared to 0.
Burst ROM Interface
Basic Timing
Rev. 6.00 Sep. 24, 2009 Page 157 of 928
Section 7 Bus Controller
REJ09B0099-0600