
72
CHAPTER 4 RESET
■
Mode Fetch
When the reset is cleared, the CPU transfers the reset vector and the mode data stored in the hardware
memory to the appropriate registers in the CPU core. The reset vector and mode data are allocated to the
four bytes from FFFFDC
H
to FFFFDF
H
. The CPU outputs these addresses to the bus immediately after the
reset is cleared and fetches the reset vector and mode data. Using mode fetching, the CPU can begin
processing at the address indicated by the reset vector.
Figure 4.4-2 shows the transfer of the reset vector and mode data.
Figure 4.4-2 Transfer of Reset Vector and Mode Data
Reference:
Whether the reset vector and the mode data are read from internal ROM or from external memory is
specified by the setting of the mode pins. If external vector mode is specified by the mode pin
settings, the CPU will always read the reset vector and the mode data from external memory instead
of from internal ROM. If single-chip mode and internal ROM external bus mode are used, setting the
mode pins to specify internal vector mode is recommended.
●
Mode data (address: FFFFDF
H
)
Only the reset operation changes the contents of the mode register. The mode register setting is valid after
a reset operation. See "8.1 Mode Setting", for details about mode data.
●
Reset vector (address: FFFFDC
H
to FFFFDE
H
)
The execution start address after the reset operation ends is written as the reset vector.
Execution starts at the address contained in the reset vector.
PCB
PC
FFFFDF
H
FFFFDE
H
FFFFDD
H
FFFFDC
H
Memory space
Mode data
Reset vector bit23 to bit16
Reset vector bit15 to bit8
Reset vector bit7 to bit0
F
2
MC-16LX CPU
register
Reset sequence
Mode
Micro-ROM
Summary of Contents for MB90460 Series
Page 1: ...The following document contains information on Cypress products ...
Page 3: ......
Page 5: ......
Page 9: ...iv ...
Page 41: ...22 CHAPTER 1 OVERVIEW ...
Page 45: ...26 CHAPTER 2 NOTES ON HANDLING DEVICES ...
Page 83: ...64 CHAPTER 3 CPU ...
Page 95: ...76 CHAPTER 4 RESET ...
Page 107: ...88 CHAPTER 5 CLOCK ...
Page 131: ...112 CHAPTER 6 LOW POWER CONSUMPTION MODE ...
Page 175: ...156 CHAPTER 7 INTERRUPT ...
Page 181: ...162 CHAPTER 8 MODE SETTING ...
Page 223: ...204 CHAPTER 9 I O PORT ...
Page 237: ...218 CHAPTER 10 TIME BASE TIMER ...
Page 247: ...228 CHAPTER 11 WATCHDOG TIMER ...
Page 275: ...256 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 373: ...354 CHAPTER 14 MULTI FUNCTIONAL TIMER ...
Page 485: ...466 CHAPTER 16 PWC Timer ...
Page 531: ...512 CHAPTER 17 UART ...
Page 559: ...540 CHAPTER 19 DELAYED INTERRUPT GENERATOR MODULE ...
Page 589: ...570 CHAPTER 20 8 10 BIT A D CONVERTER ...
Page 601: ...582 CHAPTER 21 ROM CORRECTION FUNCTION ...
Page 633: ...614 CHAPTER 23 512K 1024K BIT FLASH MEMORY ...
Page 645: ...626 CHAPTER 24 EXAMPLE OF F2 MC 16LX MB90F462 F462A F463A CONNECTION FOR SERIAL WRITING ...
Page 715: ...696 APPENDIX ...
Page 716: ...697 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 739: ......