HD64F3642AHV Datasheet, PDF (131/551 Pages) Renesas Technology Corp – Old Company Name in Catalogs and Other Documents

Figure 6.4 shows a PROM write/verify timing diagram.
Section 6 ROM
Write
Verify
Address
Data
V_PP
V_PP
V_CC
t_AS
Input data
t_DS
t_DH
t_VPS
V_CC
V_CC+1
V_CC
t_VCS
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 6.3, High-Speed, High-Reliability Programming
Flow Chart.
Figure 6.4 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 Renesas Technology specifications for the HN27C256 will
result in 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.
Rev. 6.00 Sep 12, 2006 page 109 of 526
REJ09B0326-0600