387
CHAPTER 18 SERIAL INTERFACE CHANNEL 1
(4) Automatic data transmit/receive interval specify register (ADTI)
This register sets the automatic data transmit/receive function data transfer interval.
ADTI is set with a 1-bit or 8-bit memory manipulation instruction.
RESET input clears ADTI to 00H.
Figure 18-5. Automatic Data Transmit/Receive Interval Specify Register Format (1/4)
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/f
SCK
, the minimum interval time is 2/f
SCK
.
Minimum = (n + 1)
×
+
+ 0.5
×
2
f
XX
f
SCK
+
Cautions 1.
Do not write ADTI during operation of automatic data transmit/receive function.
Bits 5 and 6 must be set to zero.
To control the data transfer interval by means of automatic transmission/reception with
ADTI, busy control (refer to 18.4.3 (4) (a) Busy control option) is invalid.
2.
3.
Remarks 1.
f
XX
: Main system clock frequency (f
X
or f
X
/2)
: Main system clock oscillation frequency
3.
f
SCK
: Serial clock frequency
2.
f
X
2
6
f
XX
28
6
f
XX
36
f
XX
1.5
f
SCK
Data Transfer Interval Specification (f
XX
= 5.0 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
18.4
s + 0.5/f
SCK
μ
31.2
s + 0.5/f
SCK
μ
44.0
s + 0.5/f
SCK
μ
56.8
s + 0.5/f
SCK
μ
69.6
s + 0.5/f
SCK
μ
82.4
s + 0.5/f
SCK
μ
95.2
s + 0.5/f
SCK
μ
108.0
s + 0.5/f
SCK
μ
120.8
s + 0.5/f
SCK
μ
133.6
s + 0.5/f
SCK
μ
146.4
s + 0.5/f
SCK
μ
159.2
s + 0.5/f
SCK
μ
172.0
s + 0.5/f
SCK
μ
184.8
s + 0.5/f
SCK
μ
197.6
s + 0.5/f
SCK
μ
210.4
s + 0.5/f
SCK
μ
Maximum
Note 2
20.0
s + 1.5/f
SCK
μ
32.8
s + 1.5/f
SCK
μ
45.6
s + 1.5/f
SCK
μ
58.4
s + 1.5/f
SCK
μ
71.2
s + 1.5/f
SCK
μ
84.0
s + 1.5/f
SCK
μ
96.8
s + 1.5/f
SCK
μ
109.6
s + 1.5/f
SCK
μ
122.4
s + 1.5/f
SCK
μ
135.2
s + 1.5/f
SCK
μ
148.0
s + 1.5/f
SCK
μ
160.8
s + 1.5/f
SCK
μ
173.6
s + 1.5/f
SCK
μ
186.4
s + 1.5/f
SCK
μ
199.2
s + 1.5/f
SCK
μ
212.0
s + 1.5/f
SCK
μ
6
5
4
3
2
1
0
7
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