Toshiba TMP91C815F Data Book page 141

7
−
bit Symbol
BR1CR
Read/Write
(020BH)
After reset 0
Always
write "0"
Function
+(16 - K) / 16 division enable
0 Disabled
1 Enabled
7
BR1ADD
Bit symbol
(020CH)
Read/Write
After Reset
Function
Baud rate generator frequency divisor setting
BR0CR <BR1S3
to BR1S0>
BR1ADD
<BR1K3 to BR1K0>
0000
0001(K = 1)
to
1111(K = 15)
(note1): The baud rate generator can be set "1" when UART mode and disable + (16 − K)/16 division
function. Don't use in I/O interface mode.
(note2): Set BR1CR <BR1ADDE> to "1" after setting K (K=1 to 15) to BR1ADD<BR1K3 to 0> when + (16
− K)/16 division function is used. However, don't use + (16 − K)/16 division function when
BR1CR<BR1S3 to 0>="0000" or "0001"(N=16 or 1).
(note3): + (16 − K)/16 division function is possible to use in only UART mode.
Set BR1CR <BR1ADDE> to "0" and disable + (16 − K)/16 division function in I/O interface mode.
Figure 3.9.12 Baud rate generator control (SIO1, BR1CR, BR1ADD)
6 5 4
BR1ADDE BR1CK1 BR1CK0
0 0 0
00: φT0
+(16−K)/16
01: φT2
division
10: φT8
0: Disable
1: Enable 11:φT32
Input clock selection for baud rate generator
Internal clock φT0
00
Internal clock φT2
01
Internal clock φT8
10
Internal clock φT32
11
6 5 4
BR1CR<BR1ADDE> = 1
0000(N = 16) 0010(N = 2)
or to
0001(N = 1) 1111(N = 15)
Disable Disable
Disabled by
Disable
N + (16 − K) / 16
91C815-138
3 2
BR1S3 BR1S2 BR1S1
R/W
0 0
Divided Frequency setting
3 2
BR1K3 BR1K2 BR1K1
R/W
0 0
Set frequency divisor K
(divided by N + (16 − K)/16)
BR1CR<BR1ADDE> = 0
0001(N = 1) (UART only)
to
1111(N = 15)
0000(N = 16)
Divided by N
TMP91C815
1 0
BR1S0
0 0
1 0
BR1K0
0 0