15
15-2
Ver.0.10
EXTERNAL BUS INTERFACE
15.1 External Bus Interface Related Signals
15.1 External Bus Interface Related Signals
The 32170 comes with external bus interface related signals shown below. These signals can be
used in external extension mode or processor mode.
(1) Address
The 32170 outputs a 20-bit address (A11-A30) for addressing any location in 2 Mbytes of space.
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The least significant A31 is not output, and in external write cycles, the 32170 outputs BHW and
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BLW signals to indicate the valid byte position at which to write on the 16-bit data bus. In read
cycles, the 32170 reads data always in 16 bits, transferring only the data read from the valid byte
position of the bus.
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(2) Chip select (CS0, CS1)
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These signals are output in external extension mode or processor mode, with CS0 and CS1
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specifying an extended external area of 2 Mbytes each. The CS0 signal points to a 2-Mbyte area in
processor mode or a 1-Mbyte area in external extension mode. (For details, refer to Chapter 3,
"Address Space.")
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(3) Read strobe (RD)
Output during external read cycle, this signal indicates the timing at which to read data from the
bus. This signal is driven high when writing to the bus or accessing the internal function.
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(4) Byte High Write/Byte High Enable (BHW / BHE)
The pin function changes depending on the Bus Mode Control Register (BUSMODC).
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When BUSMOD = 0 and this signal is Byte High Write (BHW), during external write access it
indicates that the upper byte (DB0-DB7) of the data bus is the valid data to transfer. During external
read and when accessing the internal function it outputs a high.
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When BUSMOD = 1 and this signal is Byte High Enable (BHE), during external access it indicates
that the upper byte (DB0-DB7) of the data bus is the valid data to transfer. When accessing the
internal function, it outputs a high.
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(5) Byte Low Write/Byte Low Enable (BLW / BLE)
The pin function changes depending on the Bus Mode Control Register (BUSMODC).
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When BUSMOD = 0 and this signal is Byte Low Write (BLW), during external write access it
indicates that the lower byte (DB8-DB15) of the data bus is the valid data to transfer. During
external read cycle, it outputs a high.
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When BUSMOD = 1 and this signal is Byte Low Enable (BLE), during external access it indicates
that the lower byte (DB8-DB15) of the data bus is the valid data to transfer. When accessing the
internal function, it outputs a high.
Содержание M32170F3VFP
Страница 19: ...CHAPTER 1 CHAPTER 1 OVERVIEW 1 1 Outline of the 32170 1 2 Block Diagram 1 3 Pin Function 1 4 Pin Layout ...
Страница 42: ...1 1 24 Ver 0 10 OVERVIEW 1 4 Pin Layout This is a blank page ...
Страница 56: ...2 2 14 Ver 0 10 This is a blank page ...
Страница 88: ...3 3 32 Ver 0 10 ADDRESS SPACE 3 7 Notes on Address Space This is a blank page ...
Страница 192: ...6 6 58 Ver 0 10 INTERNAL MEMORY 6 9 Precautions to Be Taken When Rewriting Flash Memory This is a blank page ...
Страница 270: ...9 9 40 Ver 0 10 DMAC 9 4 Precautions about the DMAC This is a blank page ...
Страница 498: ...10 10 228 Ver 0 10 MULTIJUNCTION TIMERS 10 9 TOM Output related 16 bit Timer This is a blank page ...
Страница 550: ...11 11 52 Ver 0 10 A D CONVERTERS 11 4 Precautions on Using A D Converters This is a blank page ...
Страница 614: ...12 12 64 Ver 0 10 This is a blank page SERIAL I O 12 9 Precautions on Using UART Mode ...
Страница 710: ...14 14 16 Ver 0 10 REAL TIME DEBUGGER RTD 14 4 Typical Connection with the Host This is a blank page ...
Страница 746: ...16 16 20 Ver 0 10 WAIT CONTROLLER 16 3 Typical Operation of the Wait Controller This is a blank page ...
Страница 756: ...17 17 10 Ver 0 10 RAM BACKUP MODE 17 4 Exiting RAM Backup Mode Wakeup This is a blank page ...
Страница 757: ...CHAPTER 18 CHAPTER 18 OSCILLATION CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit ...
Страница 762: ...18 18 6 Ver 0 10 OSCILLATION CIRCUIT 18 2 Clock Generator Circuit This is a blank page ...
Страница 798: ...19 19 36 Ver 0 10 JTAG 19 6 Precautions about Board Design when Connecting JTAG This is a blank page ...
Страница 830: ...21 21 24 Ver 0 10 PRELIMINARY PRELIMINARY This is a blank page ELECTRICAL CHARACTERISTICS 21 5 AC Characteristics ...
Страница 831: ...CHAPTER 22 CHAPTER 22 TYPICAL CHARACTERISTICS 22 1 A D Conversion Characteristics ...
Страница 833: ...Appendix 1 1 Dimensional Outline Drawing APPENDIX 1 APPENDIX 1 MECHANICAL SPECIFICATIONS ...
Страница 837: ...Appendix 2 1 32170 Instruction Processing Time APPENDIX 2 APPENDIX 2 INSTRUCTION PROCESSING TIME ...
Страница 841: ...Appendix 3 1 Precautions about Noise APPENDIX 3 APPENDIX 3 PRECAUTIONS ABOUT NOISE ...