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
2764/128
27256
S4
H
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
S5 & S6
External clock input
U
X
Internal self-induced oscillation
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
KHz oscillation
S7 & S8 & JP
M
K
4 - 5
HYNIX [ HYNIX SEMICONDUCTOR ]
