MC68HC705CT4 Datasheet, PDF (105/152 Pages) Freescale Semiconductor, Inc – General Release Specification

Freescale Semiconductor, Inc.
General Release Specification — MC68HC705CT4
Section 14. Miscellaneous Register
14.1 Contents
14.2 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .105
14.3 Miscellaneous Control Register . . . . . . . . . . . . . . . . . . . . . . .105
14.4 Miscellaneous Register Power Supply Source . . . . . . . . . . . .106
14.2 Introduction
The miscellaneous register exists to hold various system control bits. It
is located at address $0021.
14.3 Miscellaneous Control Register
Address: $0021
Bit 7
6
5
4
3
2
1
Bit 0
Read:
0
0
0
0
SPEED COE PWME
0
Write:
Reset: 0
0
0
0
0
0
0
0
Figure 14-1. Miscellaneous Control Register (MISCR)
SPEED — CPU Speed Select
This control bit, when set, selects an additional divide-by-eight after
the already divide-by-five from the oscillator clock to the internal bus
clock. This makes the internal CPU clock a divide-by-40 from the
oscillator input.
When clear, the internal bus clock is a divide-by-five from the
oscillator input. Reset clears this bit.
MC68HC705CT4 — Rev. 2.0
MOTOROLA
General Release Specification
Miscellaneous Register
105
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