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18
18-5
OSCILLATOR CIRCUIT
32180 Group User's Manual (Rev.1.0)
18.1 Oscillator Circuit
18.1.3 Oscillation Drive Capability Select Function
The microcomputer incorporates a four-stage drive capability select function.
Once the oscillation of the oscillator circuit has stabilized, the XIN-XOUT drive capability can be lowered. The
lower the drive capability, the smaller the amount of power consumption.
Clock Control Register (CLKCR)
<Address: H’0080 0786>
1
2
3
4
5
6
b7
b0
XDRVP
XDRV
0
1
1
0
0
0
0
0
<After reset: H’03>
b
Bit Name
Function
R
W
0–4
No function assigned. Fix to "0".
0
0
5
XDRVP
0
W
XDRV write control bit
6–7
XDRV
XIN-XOUT drive capability (performance ratio)
R
W
XIN-XOUT drive capability select bit
00: Low 0.25
01: 0.50
10: 0.75
11: High 1.00
(1) XDRV write control bit (XDRVP) (Bit 5)
This bit controls writing to the XIN-XOUT drive capability select bits.
(2) XIN-XOUT drive capability select bits (Bits 6, 7)
The following shows the procedure for writing to these bits.
1. Set the write control bit (XDRVP) to "1".
2. Immediately following the above, reset the write control bit (XDRVP) to "0" and write the appropriate value
to the XIN-XOUT drive capability select bits.
Note: • If a write cycle to any other area occurs between 1 and 2, write to XDRV has no effect and the
written value is not reflected. Therefore, disable interrupts and DMA transfers before setting the
drive capability control bits. Note that a pair of two consecutive writes comprise a write opera-
tion.
Содержание M32R/ECU Series
Страница 17: ...12 This page is blank for reasons of layout...
Страница 18: ...CHAPTER 1 OVERVIEW 1 1 Outline of the 32180 Group 1 2 Block Diagram 1 3 Pin Functions 1 4 Pin Assignments...
Страница 712: ...CHAPTER 18 OSCILLATOR CIRCUIT 18 1 Oscillator Circuit 18 2 Clock Generator Circuit...
Страница 794: ...CHAPTER 22 TYPICAL CHARACTERISTICS...
Страница 795: ...22 22 2 32180 Group User s Manual Rev 1 0 TYPICAL CHARACTERISTICS To be written at a later time...
Страница 796: ...APPENDIX 1 MECHANICAL SPECIFICAITONS Appendix 1 1 Dimensional Outline Drawing...
Страница 798: ...APPENDIX 2 INSTRUCTION PROCESSING TIME Appendix 2 1 32180 Instruction Processing Time...
Страница 802: ...APPENDIX 3 PROCESSING OF UNUSED PINS Appendix 3 1 Example Processing of Unused Pins...