HD6437020 Datasheet, PDF (440/507 Pages) Hitachi Semiconductor – SuperH™ RISC engine

4. You cannot write in the page programming mode. Always set the equipment to the byte
programming mode.
5. The capacity of the on-chip ROM is 32 kbytes, so the data of PROM writer addresses
H'08000–H'1FFFF should be H'FF. Always set the range for PROM addresses to H'0000–
H'7FFF.
6. When write errors occur on consecutive addresses, stop writing. Check to see if there are any
abnormalities in the EPROM writer and socket adapter.
16.3.4 Reliability After Writing
After programming, we recommend letting the device stand at high temperature (125–150°C) for
24–48 hours to increase the reliability of data retention. Letting it stand at high temperature is a
type of screening method that can get rid of initial data retention defects of the on-chip PROM's
memory cell within a short period of time. Figure 16.6 shows the flow from programming of the
on-chip PROM, including screening, to mounting on the device board.
Writing and verification
of program
Flow chart
from figure 16.4
Let stand in nonconductive,
high temperature environment
(125–150°C, 24–48 hours)
Data read and verification
(V_CC = 5.0 V)
Mount on board
Figure 16.6 Screening Flow
If abnormalities are found when the program is written and verified or the program is read and
checked after the writing/verification or letting the chip stand at high temperature, contact
Hitachi's engineering departments.
HITACHI 429