Timer Interface B (TIMB)

17.7.2 TIMB Counter Registers

The two read-only TIMB counter registers contain the high and low bytes of the value in the TIMB counter. Reading the high byte (TBCNTH) latches the contents of the low byte (TBCNTL) into a buffer. Subsequent reads of TBCNTH do not affect the latched TBCNTL value until TBCNTL is read. Reset clears the TIMB counter registers. Setting the TIMB reset bit (TRST) also clears the TIMB counter registers.

NOTE

If TBCNTH is read during a break interrupt, be sure to unlatch TBCNTL by reading TBCNTL before exiting the break interrupt. Otherwise, TBCNTL retains the value latched during the break.

Register Name and Address:

 

TBCNTH — $0052

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

 

 

 

 

 

 

 

 

 

 

Read:

Bit 15

 

Bit 14

Bit 13

Bit 12

Bit 11

Bit 10

Bit 9

Bit 8

 

 

 

 

 

 

 

 

 

 

Write:

R

 

R

R

R

R

R

R

R

 

 

 

 

 

 

 

 

 

 

Reset:

0

 

0

0

0

0

0

0

0

Register Name and Address:

 

TBCNTL — $0053

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

 

 

 

 

 

 

 

 

 

 

Read:

Bit 7

 

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

 

 

 

 

 

 

 

 

 

 

Write:

R

 

R

R

R

R

R

R

R

 

 

 

 

 

 

 

 

 

 

Reset:

0

 

0

0

0

0

0

0

0

R

= Reserved

Figure 17-6. TIMB Counter Registers (TBCNTH and TBCNTL)

17.7.3 TIMB Counter Modulo Registers

The read/write TIMB modulo registers contain the modulo value for the TIMB counter. When the TIMB counter reaches the modulo value, the overflow flag (TOF) becomes set, and the TIMB counter resumes counting from $0000 at the next timer clock. Writing to the high byte (TBMODH) inhibits the TOF bit and overflow interrupts until the low byte (TBMODL) is written. Reset sets the TIMB counter modulo registers.

Register Name and Address:

 

TBMODH — $0054

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

Read:

 

 

 

 

 

 

 

 

 

Bit 15

 

Bit 14

Bit 13

Bit 12

Bit 11

Bit 10

Bit 9

Bit 8

Write:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset:

1

 

1

1

1

1

1

1

1

Register Name and Address:

 

TBMODL — $0055

 

 

 

 

 

Bit 7

6

5

4

3

2

1

Bit 0

Read:

 

 

 

 

 

 

 

 

 

Bit 7

 

Bit 6

Bit 5

Bit 4

Bit 3

Bit 2

Bit 1

Bit 0

Write:

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset:

1

 

1

1

1

1

1

1

1

Figure 17-7. TIMB Counter Modulo Registers (TBMODH and TBMODL)

NOTE

Reset the TIMB counter before writing to the TIMB counter modulo registers.

MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1

246

Freescale Semiconductor

Page 245 Page 247
Page 246
Image 246
Freescale Semiconductor MC68HC908MR32, MC68HC908MR16 manual Timb Counter Registers, Timb Counter Modulo Registers
Page 245 Page 247

MC68HC908MR16, MC68HC908MR32 specifications

Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are part of the popular HC08 family, designed primarily for embedded applications. These microcontrollers are particularly favored in automotive, industrial, and consumer product sectors due to their reliability and versatility.

One of the standout features of the MC68HC908MR series is its CMOS technology, which enhances performance while minimizing power consumption. This makes these microcontrollers suitable for battery-operated devices. They operate at a maximum clock frequency of 2 MHz and offer a 16-bit architecture, providing a solid balance between processing power and efficiency.

The MC68HC908MR32 variant is equipped with 32KB of flash memory, which allows for the storage of complex programs and extensive data handling. In contrast, the MC68HC908MR16 features 16KB of flash memory, making it ideal for simpler applications. Both microcontrollers also come with 1KB of RAM, enabling efficient data processing and real-time operations.

Another significant characteristic of these microcontrollers is their integrated peripherals. They come with multiple input/output (I/O) pins, which allow for connectivity with various sensors and actuators. The built-in timer systems offer precise timing control for automotive and industrial applications, while the Analog-to-Digital Converter (ADC) provides essential conversion capabilities for various analog signals.

For communication purposes, the MC68HC908MR series includes a serial communication interface, enabling easy integration with other devices and systems. This versatility facilitates the development of complex systems that require interaction with external components.

Security is another crucial aspect of these microcontrollers. They have built-in fail-safe mechanisms to ensure reliable operation under various conditions, making them suitable for critical systems. Additionally, their robust architecture helps to safeguard against potential disruptions or attacks.

In summary, Freescale Semiconductor's MC68HC908MR32 and MC68HC908MR16 microcontrollers are key players in the embedded systems landscape. Their blend of power efficiency, integrated features, and scalability ensures they remain relevant for a wide array of applications, making them a favored choice among engineers and developers looking for dependable solutions in a competitive market.
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