Programming Precautions - Renesas H8 Series Hardware Manual

Figure 6.4 shows a PROM write/verify timing diagram.
Address
t
Data
t
V
PP
V
PP
t
V VPS
CC
+1
V
CC
V
CC
t
V VCS
CC
CE
OE
Note: * t is defined by the value given in figure 6.3, High-Speed, High-Reliability Programming
OPW
Flow Chart.
6.3.2

Programming Precautions

• Use the specified programming voltage and timing.
The programming voltage in PROM mode (V
permanently damage the chip. Be especially careful with respect to PROM programmer
overshoot.
Setting the PROM programmer to Renesas Technology specifications for the HN27C256 will
result in correct 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.
Write
AS
Input data
t
DS DH
t
PW
t *
OPW
Figure 6.4 PROM Write/Verify Timing
of 12.5 V.
PP
t t
OES OE
) is 12.5 V. Use of a higher voltage can
PP
Rev. 6.00 Sep 12, 2006 page 109 of 526
Section 6 ROM
Verify
t
AH
Output data
t
DF
REJ09B0326-0600