Renesas H8SX/1668R User Manual

 

R21 Analog 

Voltage 

Source 

on-board Vcc. 

Analog Voltage Source is taken 

from external connector. 

R46 

R46 Analog 

Voltage 

Source 

Analog Voltage Source is taken from 

external connector. 

R21 

R137 Analog 

Voltage 

Ground 

Analog Voltage Ground is routed to 

external connector. 

- 

Table 6-12 below describes the function of the option links associated with MCU modes. The default configuration is indicated by BOLD 

text. 

R44 MCU 

Mode, 

USB unit 

The CPU is self powered. 

J10 

 

R131 

MCU Mode 

Enables SDRAM interface. 

J14 

R130 MCU 

Mode, 

USB unit 

USB dedicated clock is 

EXTAL 

× 3

 

(choose this option if 16 MHz crystal 

is used). 

× 4

J13 

R133 

MCU Boot mode  Serial Boot Mode is selected. 

J16 

6.7. Oscillator Sources 

Two crystal oscillators are fitted on the RSK and used to supply the main clock input to the Renesas microcontroller. Table 6-13 details the 

oscillators that are fitted and alternative footprints provided on this RSK: 

Crystal (X1) 

Fitted   

12.0 MHz (HC49/4H package) 

Crystal (X2) 

Fitted 

32.768 KHz 

6.8. Reset Circuit 

The CPU Board includes a simple latch circuit that links the mode selection and reset circuit. This provides an easy method for swapping 

the device between Boot Mode and User mode. This circuit is not required on customer’s boards as it is intended for providing easy 

evaluation of the operating modes of the device on the RSK. Please refer to the hardware manual for more information on the 

requirements of the reset circuit. 

The Reset circuit operates by latching the state of the boot switch on pressing the reset button. This control is subsequently used to 

modify the mode pin states as required. 

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