GMS30004 Datasheet, PDF (52/158 Pages) Hynix Semiconductor – 4-BIT SINGLE CHIP MICROCOMPUTERS

Chapter 4. Evaluation Board
[S4] EPROM 2764/128, and 27256 can be installed by switching over the S4. For
EPROM, however, right-justify ROM chip pin 1 from socket pin 3.
Short post
S4
2764/128
H
27256
L
[S5, S6] Clock input selection
Self-induced oscillation with the external clock input and oscillator can be set by
switching over the S5 & S6
Short post
External clock input
S5 & S6
U
Internal self-induced oscillation
X
For internal clock input, install an oscillator on the PCB. Since the oscillation
circuit constant varies depending on the oscillator, adjust the constant by
referring to the oscillator manufacture`s recommendable values.
[S7, S8, JP] Clock input selection
MHz and KHz oscillation can be selected by switching over the S7, S8 and JP.
Short post
MHz oscillation
S7 & S8 & JP
M
KHz oscillation
K
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