HD404328 Datasheet, PDF (73/96 Pages) Hitachi Semiconductor – 4 BIT SINGLE CHIP MICROCOMPUTER

HD404328 Series
Warnings
1. Always specify addresses $0000 to $7FFF when programming with a PROM programmer. If address
$8000 or higher is accessed, the PROM may not be programmed or verified correctly. Set all data in
unused addresses to $FF.
Note that the plastic-package version cannot be erased and reprogrammed, but the ceramic window-
package version can be reprogrammed after being exposed to ultraviolet light.
2. Make sure that the PROM programmer, socket adapter, and LSI are aligned correctly (their pin 1
positions match), otherwise overcurrents may damage the LSI. Before starting programming, make
sure that the LSI is firmly fixed in the socket adapter and the socket adapter is firmly fixed in the
programmer.
3. PROM programmers have two voltages (V_PP): 12.5 V and 21 V. Remember that ZTAT™ devices
require a V_PP of 12.5 V—the 21-V setting will damage them. 12.5 V is the Intel 27256 setting.
Programming and Verification: The built-in PROM of the MCU can be programmed at high speed
without risk of voltage stress or damage to data reliability.
Programming and verification modes are selected as shown in table 36.
For details of PROM programming, refer to the Notes on PROM Programming section.
Table 36 PROM Mode Selection
Pin
Mode
CE
OE
V_PP
Programming
Low
High
V_PP
Verification
High Low
V_PP
Programming inhibited
High High
V_PP
O₀–O₇
Data input
Data output
High impedence
Erasure (Window Package)
Data in the PROM is erased by exposing the LSI to ultraviolet light of a wavelength of 2537 Å for an
integrated dose of at least 15 W.s/cm². These conditions can be satisfied by placing the LSI about 2 cm to
3 cm away from an ultraviolet lamp with a rating of 12,000 µW/cm² for about 20 minutes. After erasure,
all PROM bits are set to 1.
For details of packages with windows, refer to the Notes on Window Packages section.
71