HD6433832S Datasheet, PDF (132/560 Pages) Renesas Technology Corp – single-chip microcomputers

Write
Address
t_AS
Data
V_PP
V_PP
V_CC
Input data
t_DS
t_DH
t_VPS
V_CC
V_CC +1
V_CC
t_VCS
Verify
t_AH
Output data
t_DF
CE
t_PW
t_OES
t_OE
OE
t_OPW*
Note: * t_OPW is defined by the value given in figure 6-4 high-performance programming flow chart.
Figure 6.5 PROM Write/Verify Timing
6.3.2 Programming Precautions
• Use the specified programming voltage and timing.
The programming voltage in PROM mode (V_PP) is 12.5 V. Use of a higher voltage can
permanently damage the chip. Be especially careful with respect to PROM programmer
overshoot.
Setting the PROM programmer to Hitachi specifications for the HN27C256 will result in a
correct V_PP of 12.5 V.
• Make sure the index marks on the PROM programmer socket, socket adapter, and chip are
properly aligned. If they are not, the chip may be destroyed by excessive current flow. Before
programming, be sure that the chip is properly mounted in the PROM programmer.
• Avoid touching the socket adapter or chip during programming, since this may cause contact
faults and write errors.
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