32182 Datasheet, PDF (638/755 Pages) Renesas Technology Corp – 32-BIT RISC SINGLE-CHIP MICROCOMPUTER M32R FAMILY / M32R/ECU SERIES

18
OSCILLATOR CIRCUIT
18.1 Oscillator Circuit
18.1.4 System Clock Output Function
A clock whose frequency is twice that of the input clock (i.e., the peripheral clock) can be output from the BCLK
pin. The BCLK pin is shared with port P70. To use this pin to output the peripheral clock, set the P7 Operation
Mode Register (P7MOD) bit 8 to "1".
Configuration of the P7 Operation Mode Register is shown below.
P7 Operation Mode Register (P7MOD)
<Address: H’0080 0747>
b8
9
10 11 12 13 14 b15
P70MD P71MD P72MD P73MD P74MD P75MD P76MD P77MD
0
0
0
0
0
0
0
0
b
Bit Name
8
P70MD
Port P70 operation mode bit
9
P71MD
Port P71 operation mode bit
10
P72MD
Port P72 operation mode bit
11
P73MD
Port P73 operation mode bit
12
P74MD
Port P74 operation mode bit
13
P75MD
Port P75 operation mode bit
14
P76MD
Port P76 operation mode bit
15
P77MD
Port P77 operation mode bit
Function
0:P70
1:BCLK
0:P71
1:WAIT#
0:P72
1:HREQ#
0:P73
1:HACK#
0:P74
1:RTDTXD
0:P75
1:RTDRXD
0:P76
1:RTDACK
0:P77
1:RTDCLK
<After reset: H’00>
RW
RW
RW
RW
RW
RW
RW
RW
RW
18.1.5 Oscillation Stabilization Time at Power-On
The oscillator circuit comprised of a ceramic (or crystal) resonator requires a finite time before its oscillation
stabilizes after being powered on. Therefore, there must be a certain amount of oscillation stabilization time that
suits the oscillator circuit used.
Figure 18.1.5 shows an oscillation stabilization time required at power-on.
OSC-VCC
RESET#
XIN
Oscillation stabilization time
Figure 18.1.5 Oscillation Stabilization Time at Power-On
18-7
32182 Group User's Manual (Rev.1.0)