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SH7751 Group, SH7751R Group
Section 17 Smart Card Interface
R01UH0457EJ0301 Rev. 3.01
Page 733 of 1128
Sep 24, 2013
Table 17.7 Maximum Bit Rate at Various Frequencies (Smart Card Interface Mode)
Pck (MHz)
Maximum Bit Rate (bits/s)
N
n
7.1424 19200
0 0
10.00 26882
0
0
10.7136 28800
0 0
16.00 43010
0
0
20.00 53763
0
0
25.0 67204
0
0
30.0 80645
0
0
33.0 88710
0
0
50.0 67204
0
0
The bit rate error is given by the following equation:
Error (
%
) =
1488
×
2
2n – 1
×
B
×
(N + 1)
×
10
6
– 1
×
100
Pck
Table 17.8 shows the relationship between the smart card interface transmit/receive clock register
settings and the output state.
Table 17.8 Register Settings and SCK Pin State
Register Values
SCK Pin
Setting SMIF GM CKE1 CKE0
Output
State
1
*
1
1
0
0
0
Port
Determined by setting of SPB1IO
and SPB1DT bits in SCSPTR1
1 0 0 1
SCK (serial clock) output state
2
*
2
1
1
0
0
Low output
Low-level output state
1 1 0 1
SCK (serial clock) output state
3
*
2
1
1
1
0
High output
High-level output state
1 1 1 1
SCK (serial clock) output state
Notes: 1. The SCK output state changes as soon as the CKE0 bit setting is changed.
Clear the CKE1 bit to 0.
2. Stopping and starting the clock by changing the CKE0 bit setting does not affect the
clock duty cycle.