Clock Module - Renesas CPU Board M3A-HS19 User Manual

2

2.9 Clock Module

The clock module on the M3A-HS19 consists of following three blocks;
•
A block connecting X1 (oscillator) output to SH7619 EXTAL
•
A block connecting X2 (ceramic resonator) to EXTAL and XTAL (Optional)
•
A block connecting X3 (oscillator) to CK-PHY
An on-chip oscillator (15.625 MHz) is connected to the SH7619 MCU to provide an operating clock. Another on-chip
oscillator (25.000 MHz) is also connected to the MCU to provide clock to physical layer. Bus clock output is connected to
a SDRAM and expansion connectors via damping resisters respectively.
Figure 2.9.1 shows the block diagram of clock module.
* : To mount a ceramic resonator,remove the resistance R13 and mount the resistance R14.
CLK
Oscillator(X1)
15.625
CLK
Oscillator(X3)
25.000
Rev.1.01 Oct 28, .2008
REJ10J1351-0101
：Optional
R13
R14
MHz
Ceramic
resonator*(X2)
Optional
CSTCE-G15M7
(Murata)
R18
MHz
Figure 2.9.1 Clock Module
SH7619(U1)
R98
CKIO
EXTAL
R117
XTAL
CK-PHY
Features and Specifications
2.9 Clock Module
EXCLK expansion
connector(J10-36)
CLK SDRAM(U3)
2-20