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Serial Interface
13-46
Division ratio 1 = INT (IOCLK frequency / bit rate/127) + 1
Division ratio 2 = INT (IOCLK frequency / bit rate/division ratio 1 + 0.5)
Subtract 1 from the value for division ratio 2 that was derived through the above equations, and write the result in
SC3TIM.
If the value of division ratio 1 is 2 or higher, timer 2 or timer 8 must be used to divide the clock. Set SC3CK1 and
0 in the serial 3 control register SC3CTR to "01", and then set the control registers of timer 2 so that the clock is
divided by the value of division ratio 1. (Otherwise, set SC3CK1 and 0 in the serial 3 control register SC3CTR to
"11", and then set the control registers of timer 8 so that the clock is divided by the value of division ratio 1.)
If the value of division ratio 1 is 1, set SC3CK1 and 0 in the serial 3 control register SC3CTR to "00" and select
IOCLK.
The error versus the actual bit rate is calculated as follows:
Bit rate error = ABS (division ratio 1 x division ratio 2 x bit rate / IOCLK frequency – 1)
For example, when a 15 MHz IOCLK signal is used and transfer is conducted at a rate of 38.4 kbit/s, the timer
function is used to divide the clock signal. According to the equations shown above, division ratio 1 is 4 and
division ratio 2 is 98.
Set TM2BR = 3 in the timer 2 base register and SC3TIM = 97 in the serial 3 timer register, and set SC3CK1 and 0
to "01".
According to the equation shown above, the bit rate error is 0.35 %.
Tables 13-4-2 through 13-4-4 show typical examples.
Table 13-4-2
Bit Rates (1) (When IOCLK = 15 MHz)
Bit rate (bit/s)
Division ratio 1
Division ratio 2
Bit rate error
230 400
1
65
0.16 %
115 200
2
65
0.16 %
56 000
3
89
0.32 %
38 400
4
98
0.35 %
19 200
7
112
0.35 %
9 600
13
120
0.16 %
4 800
25
125
0.00 %
2 400
50
125
0.00 %
1 200
99
126
0.21 %
600
197
127
0.08 %
300
394
127
0.08 %
150
788
127
0.08 %
Note: When using a timer to divide the clock signal, subtract 1 from the value of division ratio 1 as derived from
the equations on the top of this page, and write the result in the timer base register. For details, refer to the
chapter on the 8-bit timers.
Содержание MN103001G/F01K
Страница 1: ...MICROCOMPUTER MN1030 MN103001G F01K LSI User s Manual Pub No 23101 050E ...
Страница 2: ......
Страница 4: ......
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Страница 7: ...14 A D Converter 15 I O Ports 16 Internal Flash Memory 17 Ordering Mask ROM Appendix 14 15 16 17 ...
Страница 8: ......
Страница 9: ...Table of Contents List of Figures and Tables 0 ...
Страница 26: ...xviii ...
Страница 27: ...1 0 1 General Specifications ...
Страница 35: ...2 CPU 2 ...
Страница 57: ...3 Extension Instruction Specifications 3 ...
Страница 96: ...Extension Instruction Specifications 3 40 ...
Страница 97: ...4 Memory Modes 3 4 ...
Страница 102: ...Memory Modes 4 6 ...
Страница 103: ...5 Operating Mode 5 ...
Страница 107: ...6 Clock Generator 6 13 ...
Страница 111: ...7 Internal Memory 7 ...
Страница 114: ...Internal Memory 7 4 ...
Страница 115: ...8 Bus Controller BC 8 ...
Страница 189: ...9 Interrupt Controller 9 ...
Страница 220: ...Interrupt Controller 9 32 ...
Страница 221: ...10 8 bit Timers 9 10 ...
Страница 254: ...8 bit Timers 10 34 ...
Страница 255: ...11 16 bit Timers 11 ...
Страница 292: ...16 bit Timers 11 38 ...
Страница 293: ...12 Watchdog Timer 11 12 ...
Страница 302: ...Watchdog Timer 12 10 ...
Страница 303: ...13 Serial Interface 13 ...
Страница 354: ...Serial Interface 13 52 ...
Страница 355: ...14 A D Converter 14 ...
Страница 367: ...15 I O Ports 15 ...
Страница 431: ...16 Internal Flash Memory 16 ...
Страница 439: ...17 17 Ordering Mask ROM ...
Страница 442: ...Ordering Mask ROM 17 4 ...
Страница 443: ...Appendix ...