HD6437020 Datasheet, PDF (439/507 Pages) Hitachi Semiconductor – SuperH™ RISC engine

Address
Data
V_PP
V_PP
V_CC
V_CC ^{VCC + 1}
V_CC
CE
PGM
OE
Write
t_AS
Write data
t_DS
t_DH
t_VPS
t_VCS
t_CES
t_PW
(t_OPW)
t_OES
Verify
t_AH
Read data
t_DF
t_OE
Note: t_OPW is defined as the value given in the flowchart.
Figure 16.5 Write/Verify Timing
16.3.3 Points to Note About Writing
1. Always write using the prescribed voltage and timing. The write voltage (programming
voltage) V_PP is 12.5 V (when the EPROM writer is set to the Hitachi specifications for
HN27C101, V_PP becomes 12.5 V.) Applying a voltage in excess of the rated voltage may
damage the device. Pay particular attention to overshooting in the EPROM writer.
2. Before programming, always check that the indexes of the EPROM writer socket, socket
adapter, and devices are consistent with each other. If they are not mounted in the proper
location, an overcurrent may be generated, damaging the device.
3. Do not touch the socket adapter or device during writing. Contact can cause malfunctions that
prevent data from being written accurately.
428 HITACHI