R5F21257SNFP#U0 Renesas Electronics America, R5F21257SNFP#U0 Datasheet - Page 420

• Manufacturer Part Number: R5F21257SNFP#U0
• Description: IC R8C/25 MCU FLASH 52LQFP
• Manufacturer: Renesas Electronics America
• Series: R8C/2x/25r

Specifications of R5F21257SNFP#U0

• Core Processor: R8C
• Core Size: 16/32-Bit
• Speed: 20MHz
• Connectivity: I²C, LIN, SIO, SSU, UART/USART
• Peripherals: POR, Voltage Detect, WDT
• Number Of I /o: 41
• Program Memory Size: 48KB (48K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.5K x 8
• Voltage - Supply (vcc/vdd): 2.2 V ~ 5.5 V
• Data Converters: A/D 12x10b
• Oscillator Type: Internal
• Operating Temperature: -20°C ~ 85°C
• Package / Case: 52-LQFP
• For Use With: R0K521256S000BE - KIT EVAL STARTER FOR R8C/25
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -

R8C/24 Group, R8C/25 Group
Rev.3.00
REJ09B0244-0300
Figure 19.4
19.3.2
Option Function Select Register
b7 b6 b5 b4 b3 b2 b1 b0
NOTES:
1.
2.
3. If the block including the OFS register is erased, FFh is set to the OFS register.
1
The ROM code protect function disables reading or changing the contents of the on-chip flash memory by the
OFS register in parallel I/O mode. Figure 19.4 shows the OFS Register.
The ROM code protect function is enabled by writing 0 to the ROMCP1 bit and 1 to the ROMCR bit. It disables
reading or changing the contents of the on-chip flash memory.
Once ROM code protect is enabled, the content in the internal flash memory cannot be rewritten in parallel I/O
mode. To disable ROM code protect, erase the block including the OFS register with CPU rewrite mode or
standard serial I/O mode.
The OFS register is on the flash memory. Write to the OFS register w ith a program. After w riting is completed, do not
w rite additions to the OFS register.
To use the pow er-on reset, set the LVD0ON bit to 0 (voltage monitor 0 reset enabled after reset).
Feb 29, 2008
1
ROM Code Protect Function
OFS Register
1
Bit Symbol
CSPROINI
ROMCP1
LVD0ON
WDTON
ROMCR
Symbol
OFS
(b1)
(b4)
(b6)
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—
—
—
Watchdog timer start
select bit
Reserved bit
ROM code protect
disabled bit
ROM code protect bit
Reserved bit
Voltage detection 0
circuit start bit
Reserved bit
Count source protect
mode after reset select
bit
(1)
Address
Bit Name
0FFFFh
(2)
0 : Starts w atchdog timer automatically after reset
1 : Watchdog timer is inactive after reset
Set to 1.
0 : ROM code protect disabled
1 : ROMCP1 enabled
0 : ROM code protect enabled
1 : ROM code protect disabled
Set to 1.
0 : Voltage monitor 0 reset enabled after hardw are
1 : Voltage monitor 0 reset disabled after hardw are
Set to 1.
0 : Count source protect mode enabled after reset
1 : Count source protect mode disabled after reset
reset
reset
When Shipping
Function
FFh
(3)
19. Flash Memory
RW
RW
RW
RW
RW
RW
RW
RW
RW