M16C65 Datasheet, PDF (820/829 Pages) Renesas Technology Corp – RENESAS MCU M16C FAMILY / M16C/60

Under development
M16C/65 Group
Preliminary Specification
This is a preliminary specification and is subject to change.
31. Precautions
31.27 Notes on Flash Memory
Note
P1, P4_4 to P4_7, P7_2 to P7_5, P9_1 of the 80-pin package have no external connections.
There are no P11 to P14 in the 80-pin and 100-pin packages. For the 80-pin and 100-pin
packages, do not use these pins for the entry of user boot function.
31.27.1 Functions to Prevent Flash Memory from Being Rewritten
Addresses 0FFFDFh, 0FFFE3h, 0FFFEBh, 0FFFEFh, 0FFFF3h, 0FFFF7h, and 0FFFFBh store ID
codes. When the wrong data is written to these addresses, the flash memory is prevented from being
read or written in standard serial I/O mode.
0FFFFFh is OFS1 address. When the wrong data is written to this address, the flash memory is
prevented from being read or written in parallel I/O mode.
These addresses correspond to the vector address (H) in fixed vector.
31.27.2 Reading of Data Flash
When 2.7 V ≤ VCC1 ≤ 3.0 V and f(BCLK) ≥ 16 MHz, or 3.0 V < VCC1 ≤ 5.5 V and f(BCLK) ≥ 20 MHz,
one wait state is necessary to execute the program on the data flash and read the data. Use the PM17
in the PM1 register or FMR17 bit in the FMR1 register to set one wait state.
31.27.3 CPU Rewrite Mode
31.27.3.1 Operating Speed
Set a CPU clock frequency of 10 MHz or less by the CM06 bit in the CM0 register and bits CM17 and
CM16 in the CM1 register before entering CPU rewrite mode (EW0 or EW1 mode). Also, set the
PM17 bit in the PM1 register to 1 (wait state).
31.27.3.2 Prohibited Instructions
Do not use the following instructions in EW0 mode:
UND instruction, INTO instruction, JMPS instruction, JSRS instruction, and BRK instruction.
31.27.3.3 Interrupts (EW0 Mode and EW1 Mode)
• Do not use an address match interrupt during command execution because the address match
interrupt vector is located in ROM.
• Do not use a non-maskable interrupt during block 0 erasure because fixed vector is located in block
0.
31.27.3.4 Rewrite (EW0 Mode)
If the power supply voltage drops while rewriting the block where the rewrite control program is
stored, the rewrite control program is not correctly rewritten. This may prevent the flash memory from
being rewritten. If this error occurs, use standard serial I/O mode or parallel I/O mode for rewriting.
REJ09B0484-0030 Rev.0.30 Sep 09, 2008
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