Carrier Modulator Transmitter (CMT)

Modulator

9.5.4 Modulator Period Data Registers (MDR1, MDR2, and MDR3)

The 12-bit MBUFF and SBUFF registers are accessed through three

8-bit registers: MDR1, MDR2, and MDR3. MDR2 and MDR3 contain the least significant eight bits of MBUFF and SBUFF respectively. MDR1 contains the two most significant nibbles of MBUFF and SBUFF. In many applications, periods greater than those obtained by eight bits will not be required. Dividing the registers in this manner allows the user to clear MDR1 and generate 8-bit periods with just two data writes.

Address: $0015

 

 

 

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

 

 

 

 

 

 

 

 

Read:

MB11

MB10

MB9

MB8

SB11

SB10

SB9

SB8

Write:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset:

 

 

Unaffected by Reset

 

 

 

Figure 9-11. Modulator Period Data Register MDR1

Address: $0016

 

 

 

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

 

 

 

 

 

 

 

 

Read:

MB7

MB6

MB5

MB4

MB3

MB2

MB1

MB0

Write:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset:

 

 

Unaffected by Reset

 

 

 

Figure 9-12. Modulator Period Data Register MDR2

Address: $0017

 

 

 

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

 

 

 

 

 

 

 

 

Read:

SB7

SB6

SB5

SB4

SB3

SB2

SB1

SB0

Write:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset:

 

 

Unaffected by Reset

 

 

 

Figure 9-13. Modulator Period Data Register MDR3

MC68HC05RC16 — Rev. 3.0

 

General Release Specification

 

 

 

MOTOROLA

Carrier Modulator Transmitter (CMT)

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