CONNECTION WITH EXTERNAL DEVICES
12.1 Signals required for accessing external devices
7751 Group User’s Manual
12–8
12.1.2 Operation of bus interface unit (BIU)
Figures 12.1.5 and 12.1.6 show the examples of operating waveforms of the signals input and output to
/from externals when accessing external devices. The following explains these waveforms compared with
the basic operating waveform (refer to section “2.2.3 Operation of bus interface unit (BIU).”)
(1)
When fetching instructions into instruction queue buffer
➀
When the instruction which is next fetched is located at an even address in the 16-bit external data
bus width, the BIU fetches 2 bytes at a time with the waveform (a). When in the 8-bit external data
bus width, the BIU fetches only 1 byte with the first half of waveform (e).
➁
When the instruction which is next fetched is located at an odd address in the 16-bit external data
bus width, the BIU fetches only 1 byte with the waveform (d). When in the 8-bit external data bus
width, the BIU fetches only 1 byte with the first half of waveform (f).
When a branch to an odd address is caused by a branch instruction and others in the 16-bit external
data bus width, the BIU first fetches 1 byte in waveform (d), and after that, fetches each two bytes
at a time in waveform (a).
(2)
When reading or writing data to and from memory•I/O device
➀
When accessing 16-bit data which begins at an even address, waveform (a) or (e) is applied.
➁
When accessing 16-bit data which begins at an odd address, waveform (b) or (f) is applied.
➂
When accessing 8-bit data at an even address, waveform (c) or the first half of (e) is applied.
➃
When accessing 8-bit data at an odd address, waveform (d) or the first half of (f) is applied.
For instructions that are affected by the data length flag (m) and the index register length flag (x),
operation
➀
or
➁
is applied when flag m or x = “0”; operation
➂
or
➃
is applied when flag m or x
= “1.”
The setup of flags m and x and the selection of the external data bus width do not affect each other.
Содержание 7700 FAMILY
Страница 2: ...MITSUBISHI 16 BIT SINGLE CHIP MICROCOMPUTER 7700 FAMILY 7751 SERIES 7751 Group User s Manual...
Страница 11: ...Table of Contents viii 7751 Group User s Manual MEMORANDUM...
Страница 12: ...CHAPTER 1 DESCRIPTION 1 1 Performance overview 1 2 Pin configuration 1 3 Pin description 1 4 Block diagram...
Страница 48: ...CHAPTER 3 INPUT OUTPUT PINS 3 1 Programmable I O ports 3 2 I O pins of internal peripheral devices...
Страница 157: ...TIMER B 6 28 7751 Group User s Manual 6 5 Pulse period pulse width measurement mode MEMORANDUM...
Страница 245: ...7751 Group User s Manual 8 36 A D CONVERTER Precautions when using A D converter MEMORANDUM...
Страница 246: ...CHAPTER 9 WATCHDOG TIMER 9 1 Block description 9 2 Operation description 9 3 Precautions when using watchdog timer...
Страница 254: ...CHAPTER 10 STOP MODE 10 1 Clock generating circuit 10 2 Operation description 10 3 Precautions for Stop mode...
Страница 260: ...CHAPTER 11 WAIT MODE 11 1 Clock generating circuit 11 2 Operation description 11 3 Precautions for Wait mode...
Страница 265: ...7751 Group User s Manual WAIT MODE 11 6 11 3 Precautions for Wait mode MEMORANDUM...
Страница 289: ...CONNECTION WITH EXTERNAL DEVICES 12 4 Hold function 7751 Group User s Manual 12 24 MEMORANDUM...
Страница 290: ...CHAPTER 13 RESET 13 1 Hardware reset 13 2 Software reset...
Страница 302: ...CHAPTER 14 CLOCK GENERATING CIRCUIT 14 1 Oscillation circuit example 14 2 Clock...
Страница 307: ...CLOCK GENERATING CIRCUIT 7751 Group User s Manual 14 6 14 2 Clock MEMORANDUM...
Страница 359: ...ELECTRICAL CHARACTERISTICS 7751 Group User s Manual 15 52 MEMORANDUM 15 15 Testing circuit for ports P0 to P8 1 and E...
Страница 360: ...CHAPTER 16 STANDARD CHARACTERISTICS 16 1 Standard characteristics...
Страница 365: ...STANDARD CHARACTERISTICS 16 1 Standard characteristics 7751 Group User s Manual 16 6 MEMORANDUM...
Страница 366: ...CHAPTER 17 APPLICATIONS 17 1 Memory expansion...
Страница 405: ...APPLICATIONS 7751 Group User s Manual 17 40 17 1 Memory expansion MEMORANDUM...
Страница 406: ...CHAPTER 18 PROM VERSION 18 1 EPROM mode 18 2 Usage precaution...
Страница 417: ...7751 Group User s Manual PROM VERSION 18 12 18 2 Usage precaution MEMORANDUM...
Страница 418: ...CHAPTER 19 FLASH MEMORY VERSION 19 1 Parallel input output mode 19 2 Serial input output mode...
Страница 451: ...FLASH MEMORY VERSION 7751 Group User s Manual 19 34 19 2 Serial input output mode MEMORANDUM...
Страница 483: ...APPENDIX 7751 Group User s Manual 20 32 Appendix 4 Package outlines Appendix 4 Package outlines 80P6N A...
Страница 484: ...APPENDIX 7751 Group User s Manual 20 33 Appendix 4 Package outlines 80D0...
Страница 489: ...APPENDIX 7751 Group User s Manual 20 38 Appendix 6 Hexadecimal instruction code table...
Страница 490: ...APPENDIX 7751 Group User s Manual 20 39 Appendix 6 Hexadecimal instruction code table...
Страница 491: ...APPENDIX 7751 Group User s Manual 20 40 Appendix 7 Machine instructions Appendix 7 Machine instructions...
Страница 492: ...APPENDIX 7751 Group User s Manual 20 41 Appendix 7 Machine instructions...
Страница 493: ...APPENDIX 7751 Group User s Manual 20 42 Appendix 7 Machine instructions...
Страница 494: ...APPENDIX 7751 Group User s Manual 20 43 Appendix 7 Machine instructions...
Страница 495: ...APPENDIX 7751 Group User s Manual 20 44 Appendix 7 Machine instructions...
Страница 496: ...APPENDIX 7751 Group User s Manual 20 45 Appendix 7 Machine instructions...
Страница 497: ...APPENDIX 7751 Group User s Manual 20 46 Appendix 7 Machine instructions...
Страница 498: ...APPENDIX 7751 Group User s Manual 20 47 Appendix 7 Machine instructions...
Страница 499: ...APPENDIX 7751 Group User s Manual 20 48 Appendix 7 Machine instructions...
Страница 500: ...APPENDIX 7751 Group User s Manual 20 49 Appendix 7 Machine instructions...
Страница 501: ...APPENDIX 7751 Group User s Manual 20 50 Appendix 7 Machine instructions...
Страница 502: ...APPENDIX 7751 Group User s Manual 20 51 Appendix 7 Machine instructions...
Страница 503: ...APPENDIX 7751 Group User s Manual 20 52 Appendix 7 Machine instructions...
Страница 504: ...APPENDIX 7751 Group User s Manual 20 53 Appendix 7 Machine instructions...
Страница 505: ...APPENDIX 7751 Group User s Manual 20 54 Appendix 7 Machine instructions...
Страница 506: ...APPENDIX 7751 Group User s Manual 20 55 Appendix 7 Machine instructions...
Страница 507: ...APPENDIX 7751 Group User s Manual 20 56 Appendix 7 Machine instructions...
Страница 508: ...APPENDIX 7751 Group User s Manual 20 57 Appendix 7 Machine instructions...
Страница 509: ...APPENDIX 7751 Group User s Manual 20 58 Appendix 7 Machine instructions...
Страница 510: ...APPENDIX 7751 Group User s Manual 20 59 Appendix 7 Machine instructions...
Страница 511: ...APPENDIX 7751 Group User s Manual 20 60 Appendix 7 Machine instructions...
Страница 535: ...APPENDIX Appendix 9 Q A 7751 Group User s Manual 20 84 MEMORANDUM...
Страница 536: ...GLOSSARY...
Страница 539: ...GLOSSARY 7751 Group User s Manual 4 MEMORANDUM...