Renesas MCU M16C Family (R32C/M32C/M16C/R8C) - Glyn

Reset Function (On-Chip Reset Circuit)
• Voltage-Drop Interrupt (Enabled/Disabled by Software)
Enables software detection of power supply voltage drops without external circuitry.
• On-Chip Reset Circuit (Enabled/Disabled by Software)
Prevents malfunctions caused by voltage dropping below the guaranteed operation voltage.
RESET
IC
Vcc Vcc [V]
Reset Cleared
Voltage Detection Function Started by Software
Voltage Drop Interrupt
5.0 Vcc
4.0
2.7
0
Approx. 0.3Vcc
Reset Pin
CPU
RESET
IC
No external reset
IC needed.
RESET
IC
CPU
(Normal Operation)
Reset
Reset Cleared
Optional Function Select Register
• Several optional functions can be present in the flash memory.
• Clock source of the watchdog timer can be selected before the reset.
• Rom code can be protected against illegal access.
• Low voltage detection function can be enabled before the reset.
Optional Function Select Register (Address 0FFFFH)
5.0
Vdet2
Vdet1
Vdet0
Reset Cleared
0
CPU
RESET
IC
No external reset
IC needed.
RESET
IC
CPU
bit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
CSPROINI LVD0ON ROMCP1 ROMCR WDTON
Other Functions
CRC
The CRC function can be used to improve data reliability.
• On-chip hardware performs CRC calculations in two cycles.
• Generating polynomial: X16 + X12 + X5 + 1 (CCITT standard)
• Provides more powerful error verification than parity or checksum methods.
RAM
Send Data 0
1
2
CRC
CRC
0
1
Data Input
Calculated in
2 Cycles
8-Bit Data
CRC Input Register
CRC Code
Generator Circuit
X 16 + X 12 + X 5 + 1
CRC Data Register
16-Bit Code
• The number of external reset ICs can be reduced.
• Setting can be made before reset clearing using
the optional function select register.
RESET
IC
Vcc
0.8Vcc or Above
Reset
Reset Pin
Reset/Interrupt
X-Y Data Converter
Performs high-speed flipping,
rotation, enlargement,
and reduction of image data.
Rotation (Flipping)
Reset Cleared
Enlargement Reduction
Faster Image Recognition
Z-Axis Bit Count
Y-Axis Bit Count
20