Communication Prescaler Control Register 1 (Cdcr1) - Fujitsu MB90895 Series Hardware Manual

CHAPTER 15 UART1
15.3.5

Communication Prescaler Control Register 1 (CDCR1)

The communication prescaler control register 1 (CDCR1) is used to set the baud rate of
the dedicated baud rate generator for the UART1.
• Starts/stop the communication prescaler
• Sets the division ratio for machine clock
I Communication Prescaler Control Register 1 (CDCR1)
Figure 15.3-7 Communication Prescaler Control Register 1 (CDCR1)
15
14
R/W
R/W : Read/Write
X : Undefined
: Unused
: Reset value
Table 15.3-5 Functions of Communication Prescaler Control Register 1 (CDCR1) (1/2)
bit8
to
bit10
bit11
bit12
to
bit14
446
13 12 11 10 9 8
R/W R/W R/W R/W
bit name
DIV0 to DIV2:
Communication
prescaler division ratio
bits
Reserved: reserved bit
Unused bits
Reset value
0XXX0000
B
bit10 bit9 bit8
DIV2 DIV1 DIV0
Communication prescaler division ratio (div) bit
0 0 0
0 0 1
0 1 0
0 1 1
1 0 0
1 0 1
1 1 0
1 1 1
bit11
Reserved
0
Be sure to set to "0".
bit15
MD Communication prescaler control bit
0
Communication prescaler operating stop
1 Communication prescaler operating enabled
Function
• These bits set the machine clock division ratio.
Note:
When changing the division ratio, the time of at least two
clock cycles of the division clock should be allowed before
the next communication is started in order to stabilize the
clock frequency.
Be sure to set this bit to "0".
Read: The value is undefined.
Write: No effect
Divided by 1
Divided by 2
Divided by 3
Divided by 4
Divided by 5
Divided by 6
Divided by 7
Divided by 8
Reserved bit