Renesas M16C Series User Manual

Clock-Asynchronous Serial I/O
M30240 Group
Rev.1.00 Sep 24, 2003 Page 226 of 360
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.
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
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
Let X
IN
= 12 MHz, Timer Ai counter = 3, bit rate generator = 0, F = 1860, and D = 1, then the value to
be set in the Timer Aj counter becomes Timer Aj counter = 464
Timer Aj counter = 464
Figure 2.74: Example of connnection
Bit rate generator +1
1
16
x = f1 x
1
f1 x
Timer Ai counter +1
1
x x
1
F/D
1
2
Bit rate generator +1
1
16
x = 12 x
1
12 x x
1
372/1
1
2
1
2
x
Timer Aj counter +1
x
x
1
f1 x
Bit generator +1
1
x
x
1
F/D
1
16
Bit rate generator +1
x
1
= f1 x
1
2
1
2
Timer Aj counter +1
1
2
x
= 12 x
1
12 x
x
1
1860/1
1
2
1
3 + 1
xx
1
0 + 1
1
16
x
Clock generator
UART2 Clock
UART
CLK
UART Clock
UART
1
F/D
SIM Card
M30240M6
1/2Timer Ai counter
Timer Aj counter 1/2
UART2 bit rate generator
1/16
RxD2
TxD2
SIM card
internal clock
frequency
division ratio
TAiOUT
TAjOUT
CLK2External clock
f1
Xin

Renesas M16C Series Specifications

General

Brand	Renesas
Model	M16C Series
Category	Computer Hardware
Language	English