NEC PD75402A, PD75P402 user manual Clock Output Mode Register Clom

CHAPTER 5. PERIPHERAL HARDWARE FUNCTIONS

5.3.2Clock Output Mode Register (CLOM)

CLOM is a 4-bit register used to control clock output.

CLOM is set by a 4-bit memory handling instruction. Bit handling instructions cannot be used. Also, this register cannot be read.

RESET input clears CLOM to zero and selects the clock output disabled state.

Fig. 5-19 Clock Output Mode Register Format

Address	3	2	1	0
FD0H	CLOM3	0	CLOM1	CLOM0

Symbol

CLOM

Clock output frequency selection bits ( ) : When fXX = 4.19 MHz

0	0	Φ output* (1.05 MHz, 524 kHz, 65.5 kHz)
0	1
		Setting prohibited
1	0
1	1	fXX/26 output (65.5 kHz)

*Φ is the CPU clock selected by PCC

Clock output enable/disable bit

0Output disabled

0Output enabled

Note Ensure that 0 is written to bit 2 of CLOM.

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