NEC Figure 18-5. Automatic Data Transmit/Receive Interval Specify Register Format (3/4), 2628 f 2636 f, 0.5, 1.5

397
CHAPTER 18 SERIAL INTERFACE CHANNEL 1
Data Transfer Interval Specification (f XX = 2.5 MHz Operation)
ADTI4 ADTI3 ADTI2 ADTI1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
Minimum
Note 2
36.8 s + 0.5/f SCK
62.4 s + 0.5/f SCK
88.0 s + 0.5/f SCK
113.6 s + 0.5/f SCK
139.2 s + 0.5/f SCK
164.8 s + 0.5/f SCK
190.4 s + 0.5/f SCK
216.0 s + 0.5/f SCK
241.6 s + 0.5/f SCK
267.2 s + 0.5/f SCK
292.8 s + 0.5/f SCK
318.4 s + 0.5/f SCK
344.0 s + 0.5/f SCK
369.6 s + 0.5/f SCK
395.2 s + 0.5/f SCK
420.8 s + 0.5/f SCK
Maximum
Note 2
40.0 s + 1.5/f SCK
65.6 s + 1.5/f SCK
91.2 s + 1.5/f SCK
116.8 s + 1.5/f SCK
142.4 s + 1.5/f SCK
168.0 s + 1.5/f SCK
193.6 s + 1.5/f SCK
219.2 s + 1.5/f SCK
244.8 s + 1.5/f SCK
270.4 s + 1.5/f SCK
296.0 s + 1.5/f SCK
321.6 s + 1.5/f SCK
347.2 s + 1.5/f SCK
372.8 s + 1.5/f SCK
398.4 s + 1.5/f SCK
424.0 s + 1.5/f SCK
65432107
Symbol
ADTI ADTI7 0 0 ADTI4 ADTI3 ADTI2 ADTI1 ADTI0 FF6BH 00H R/W
Address After Reset R/W
ADTI7
0
Data Transfer Interval Control
No control of interval by ADTI
Note 1
Control of interval by ADTI (ADTI0 to ADTI4)
1
ADTI0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
µ
Figure 18-5. Automatic Data Transmit/Receive Interval Specify Register Format (3/4)
Notes 1. The interval is dependent only on CPU processing.
2. The data transfer interval includes an error. The data transfer minimum and maximum intervals
are found from the following expressions (n: Value set in ADTI0 to ADTI4). However, if a
minimum which is calculated by the following expressions is smaller than 2/fSCK, the minimum
interval time is 2/fSCK.
Minimum = (n+1) × ++
Maximum = (n+1) × ++
Cautions 1. Do not write ADTI during operation of automatic data transmit/receive function.
2. Bits 5 and 6 must be set to zero.
3. If the auto send and receive data transmission interval time is controlled using ADTI,
busy control becomes invalid (see 18.4.3 (4) (a) Busy control option).
Remarks 1. fXX : Main system clock frequency (fX or fX/2)
2. fX: Main system clock oscillation frequency
3. fSCK : Serial clock frequency
2628
fXX fXX
2636
fXX fXX
0.5
fSCK
1.5
fSCK