15
15-9
EXTERNAL BUS INTERFACE
32180 Group User’s Manual (Rev.1.0)
15.2.3 Bus Mode Control Register
Bus Mode Control Register (BUSMODC)
<Address: H’0080 077F>
9
10
11
12
13
14
b15
b8
BUSMOD
0
0
0
0
0
0
0
0
<After reset: H’00>
b
Bit Name
Function
R
W
8–14
No function assigned. Fix to "0".
0
0
15
BUSMOD
0: WR signal separate mode
R
W
Bus mode control bit
1: Byte enable separate mode
This register is used to facilitate memory connections during processor mode and external extension mode.
When the Bus Mode Control bit (BUSMOD) = "0", the WR# signal is output separately for each byte area.
Signals RD#, BHW#, BLW#, BCLK# and WAIT# can be used.
When the Bus Mode Control bit (BUSMOD) = "1", the byte enable signal is output separately for each byte area.
Signals RD#, BHE#, BLE#, WR# and WAIT# can be used. In a WAIT control circuit configuration, because
BCLK output is not available, timing must be controlled external to the chip.
Note: • Any external bus area must temporarily be accessed for read or write before the Bus Mode
Control bit (BUSMOD) can be set to "1" (= byte enable separate mode).
For memory connection in boot mode, the Bus Mode Control Register has no effect, and the microcomputer
operates in the same way as when the Bus Mode Control bit (BUSMOD) is cleared to "0".
Figure 15.2.1 Pin Functions when External Bus Modes are Changed
CS0#–CS3#
DB0–DB15
WAIT#
RD#
BHW#
BLW#
A11–A30
CS0#–CS3#
DB0–DB15
WAIT#
RD#
WR#
BHE#
BLE#
A11–A30
BCLK
BUSMOD bit = 0
BUSMOD bit = 1
15.2 External Bus Interface Related Registers
Summary of Contents for M32R/ECU Series
Page 17: ...12 This page is blank for reasons of layout...
Page 712: ...CHAPTER 18 OSCILLATOR CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit...
Page 794: ...CHAPTER 22 TYPICAL CHARACTERISTICS...
Page 796: ...APPENDIX 1 MECHANICAL SPECIFICAITONS Appendix 1 1 Dimensional Outline Drawing...
Page 798: ...APPENDIX 2 INSTRUCTION PROCESSING TIME Appendix 2 1 32180 Instruction Processing Time...
Page 802: ...APPENDIX 3 PROCESSING OF UNUSED PINS Appendix 3 1 Example Processing of Unused Pins...