DF3048BVX25V Renesas Electronics America, DF3048BVX25V Datasheet - Page 643

• Manufacturer Part Number: DF3048BVX25V
• Description: MCU 3/5V 128K PB-FREE 100-TQFP
• Manufacturer: Renesas Electronics America
• Series: H8® H8/300Hr

Specifications of DF3048BVX25V

• Core Processor: H8/300H
• Core Size: 16-Bit
• Speed: 25MHz
• Connectivity: SCI, SmartCard
• Peripherals: DMA, PWM, WDT
• Number Of I /o: 70
• Program Memory Size: 128KB (128K x 8)
• Program Memory Type: FLASH
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 3 V ~ 3.6 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: Lead free / RoHS Compliant
• Eeprom Size: -

18.9
As flash memory programming and erasing takes time, it may be difficult to carry out tuning by
writing parameters and other data in real time. In this case, real-time programming of flash
memory can be emulated by overlapping part of RAM (H'FFF000–H'FFF3FF) onto a small block
area in flash memory. This RAM area change is executed by means of bits 3 to 1 in the RAM
control register (RAMCR). After the RAM area change, access is possible both from the area
overlapped onto flash memory and from the original area (H'FFF000–H'FFF3FF). For details of
RAMCR and the RAM area setting method, see section 18.5.4, RAM Control Register (RAMCR).
Example of Emulation of Real-Time Flash Memory Programming
In the following example, RAM area H'FFF000–H'FFF3FF is overlapped onto flash memory area
EB2 (H'000800–H'000BFF).
Block area
Note: * When part of RAM (H'FFF000 H'FFF3FF) is overlapped onto a flash memory small block area, the flash
EB2
area
Flash Memory Emulation in RAM
Section 18 ROM (H8/3048F-ONE: Single Power Supply, H8/3048B Mask ROM Version)
memory in the overlapped area cannot be accessed. It can be accessed when the overlapping is
cleared.
H'000000
H'000800
H'000BFF
H'000FFF
Figure 18.16 Example of RAM Overlap Operation
Flash memory
space
*
H'FFEF10
H'FFEFFF
H'FFF000
H'FFF3FF
H'FFF400
H'FFFF0F
Overlapping RAM
(Mapping RAM
On-chip RAM
(Actual RAM
area)
area
area)
Rev. 3.00 Sep 27, 2006 page 615 of 872
Procedure:
1. Part of RAM (H'FFF000
2.
3. The programmed data is checked,
4. The data written in RAM area
H'FFF3FF) is overlapped onto the
area (EB2) requiring real-time
programming.
(RAMCR bits 3 1 are set to 1, 1, 0,
and the flash memory area to be
overlapped (EB2) is selected.)
performed using the overlapping
RAM.
then RAM overlapping is cleared.
(RAMS bit is cleared.)
H'FFF000 H'FFF3FF is written to
flash memory space.
Real-time programming is
REJ09B0325-0300