SH7730 Datasheet, PDF (889/1188 Pages) Renesas Technology Corp – Renesas 32-Bit RISC Microcomputer SuperHTM RISC engine Family / SH7780 Series

Section 25 SIM Card Module (SIM)
25.4.4 Clocks
Only the internal clock generated by the on-chip baud rate generator can be used as the
transmit/receive clock in the smart card interface. The bit rate is set using the bit rate register
(SCBRR) and the sampling register (SCSMPL), using the formula indicated below. Examples of
bit rates are listed in table 25.5.
Here, when the CKE0 bit is set to 1 and the clock output is selected, a clock signal is output from
the SIM_CLK pin with frequency equal to (SCSMPL + 1) times the bit rate.
B = Pφ × 10⁶ /{(S+1) × 2 (N+1)}
where
B = Bit rate (bits/s)
Pφ = Operating frequency of the peripheral module
S = SCSMPL setting (0 ≤ S ≤ 2047)
N = SCBRR setting (0 ≤ N ≤ 7).
Table 25.5 Example of Bit Rates (bits/s) for SCBRR Settings
(Pφ = 19.8 MHz, SCSMPL = 371)
SCBRR Setting
SCK Frequency (MHz)
Bit Rate (bits/s)
7
1.2375
3327
6
1.414
3802
5
1.65
4435
4
1.98
5323
3
2.475
6653
2
3.3
8871
1
4.95
13306
0
9.9
26613
Note: The bit rate is a value that is rounded off below the decimal point.
Rev. 1.00 Sep. 19, 2007 Page 841 of 1136
REJ09B0359-0100