Prom Programming; Operating Modes - NEC PD78056F User Manual

26.3 PROM Programming

The PD78P058F and 78P058FY include on-chip PROM in a 60 Kbyte configuration as program memory. To
write a program into the PD78P058F or 78P058FY PROM, make the device enter the PROM programming
mode by setting the levels of the V
paragraph (2) PROM programming mode in section 1.5 or 2.5 Pin Configuration (Top View).
Caution Write the program in the range of addresses 0000H to EFFFH (specify the last address as
EFFFH.) The program cannot be correctly written by a PROM programmer which does not have
a write address specification function.

26.3.1 Operating modes

When +5 V or +12.5 V is applied to the V
and PD78P058FY are set to the PROM programming mode. This is one of the operating modes shown in Table
26-4 below according to the setting of the CE, OE, and PGM pins.
The PROM contents can be read by setting the read mode.
Operating Mode
Page data latch
Page write
Byte write
Program verify
Program inhibit
Read
Output disabled
Standby
Remark : L or H
(1) Read mode
Read mode is set by setting CE to L and OE to L.
(2) Output disable mode
If OE is set to H, data output becomes high impedance and the output disable mode is set.
Therefore, if multiple PD78P058Fs or 78P058FYs are connected to the data bus, data can be read from any
one device by controlling the OE pin.
540
CHAPTER 26 PD78P058F, 78P058FY
and RESET pins as specified. For the connection of unused pins, see
PP
pin and a low-level signal is applied to the RESET pin, the PD78P058F
PP
Table 26-4. PROM Programming Operating Modes
Pin
RESET V
PP
+12.5 V +6.5 V
L
+5 V
V CE OE PGM
DD
H L H
H H L
L H L
L L H
H H
L L
L L H
+5V L H
H
D0 to D7
Data input
High impedance
Data input
Data output
High impedance
Data output
High impedance
High impedance