tmp19a44fda TOSHIBA Semiconductor CORPORATION, tmp19a44fda Datasheet - Page 356

• Manufacturer Part Number: tmp19a44fda
• Description: 32bit Tx System Risc
• Manufacturer: TOSHIBA Semiconductor CORPORATION

14.2.1 Baud Rate Generator
Serial Channel (SIO)
•
•
•
The baud rate generator generates transmit and receive clocks to determine the serial channel transfer
rate.
The baud rate generator uses either the φT1, φT4, φT16 or φT64 clock supplied from the 7-bit prescaler.
This input clock selection is made by setting the baud rate setting register, BR0CR <BR0CK1:0>.
The baud rate generator contains built-in dividers for divide by 1, (N + m/16), and 16 where N is a
number from 2 to 15 and m is a number from 0 to 15. The division is performed according to the
settings of the baud rate control registers BR0CR <BR0ADDE> <BR0S3:0> and BR0ADD
<BR0K3:0> to determine the resulting transfer rate.
UART Mode:
I/O interface mode:
Baud rate calculation to use the baud rate generator:
1)
2)
1)
2)
If BR0CR <BR0ADDE> = 0,
The setting of BR0ADD <BR0K3:0> is ignored and the counter is divided by N where N is
the value set to BR0CR <BR0S3:0>. (N = 1 to 16).
If BR0CR <BR0ADDE> = 1,
The N + (16 - K)/16 division function is enabled and the division is made by using the values
N (set in BR0CR <BR0S3:0>) and K (set in BR0ADD<BR0K3:0>). (N = 2 to 15, K = 1 to
15)
Note
The N + (16 - K)/16 division function cannot be used in the I/O interface mode. Be sure to
divide by N, by setting BR0CR <BR0ADDE> to "0."
Baud rate =
The highest baud rate out of the baud rate generator is 625 kbps when φT1 is 20 MHz.
The fsys/2 frequency, which is independent of the baud rate generator, can be used as the
serial clock. In this case, the highest baud rate will be 2.5 Mbps when fsys is 80 MHz.
Baud rate =
The highest baud rate will be generated when φT1 is 20 MHz. If double buffering is used, the
divide ratio can be set to "1" and the resulting output baud rate will be 10 Mbps. (If double
UART mode
I/O interface mode
For the N values of 1 and 16, the above N+(16-K)/16 division function
is inhibited. So, be sure to set BR0CR<BR0ADDE> to "0."
Frequency
Frequency
Baud
Baud
TMP19A44(rev1.3) 14-4
rated
rated
divided
divided
generator
generator
by the
by the
input
input
divide
divide
clock
clock
ratio
ratio
/16
/2
TMP19A44
2010-04-01