Sim Interface Compliance - Renesas M16C Series User Manual

M30240 Group

2.5.3 SIM Interface Compliance

In conforming to the SIM interface, the UART clock signal within the SIM card needs to conform to the
UART2 clock signal within the microprocessor. Two examples are given here as means of generating a
UART2 clock signal within the microprocessor.
• In the case of setting a value equal to or less than (1/256 X 1/16) in the division rate of UART2 clock,
choose f1 for the UART's source clock signal and set an optional value in the bit rate generator.
• In the case of setting a value equal to or greater than (1/256 X 1/16) in the division rate of UART2 clock,
set the bit rate generator to "0", turn the source clock signal to timer output and set an optional value
in the timer.
Let F be the clock signal within the SIM card and D be the bit rate adjustment factor, then the formula
for the UART clock signal becomes as follows. Figure 2.74 shows an example connection.
• In the case of setting a value equal to or less than (1/256 X 1/16) in the division rate of UART2 clock:
UART2 clock signal within microprocessor = UART clock within SIM card.
1
f1 x
Bit rate generator +1
Let XIN = 12 MHz, Timer Ai counter = 1, F = 372, and D = 1, then the value to be set in the bit rate
generator becomes
1
12 x
Bit rate generator +1
Bit rate generator = 92
• In the case of setting a value equal to or greater than (1/256 X 1/16) in the division rate of UART2 clock:
UART2 clock signal within microprocessor = UART clock within SIM card
1
f1 x
Timer Aj counter +1
1
= f1 x Bit rate generator +1 x
Let X = 12 MHz, Timer Ai counter = 3, bit rate generator = 0, F = 1860, and D = 1, then the value to
IN
be set in the Timer Aj counter becomes Timer Aj counter = 464
1
12 x
Timer Aj counter +1
Timer Aj counter = 464
Figure 2.74: Example of connnection
Rev.1.00 Sep 24, 2003 Page 226 of 360
1
x = f1 x
16 Timer Ai counter +1
1
1
x = 12 x
x
16
2
1
x
x
2
Bit generator +1
1
1
x
2
F/D
1
1
1
x
x
x
2
0 + 1
16
Clock generator
Xin M30240M6
Timer Ai counter 1/2
Timer Aj counter 1/2
f1 External clock
UART2 bit rate generator
1/16
UART2 Clock
UART
Clock-Asynchronous Serial I/O
1
1
x x
2
1 1
x
2 372/1
1
1
x
16
1 1
= 12 x
x
x
3 + 1 2
SIM Card
TAiOUT
CLK
TAjOUT SIM card
1
internal clock
frequency
F/D
division ratio
CLK2
UART Clock
UART
RxD2
TxD2
1
F/D
1
1860/1