4
REV. 4.4 , AUG. 20, 2001
P/N: PM0156
MX27C1100/27C1024
VIL(for MX27C1024), OE at VIL, CE at VIH(for 
MX27C1100)and VPP at its programming voltage.
AUTO IDENTIFY MODE
The auto identify mode allows the reading out of a binary 
code from an EPROM that will identify its manufacturer 
and device type. This mode is intended for use by 
programming equipment for the purpose of 
automatically matching the device to be programmed 
with its corresponding programming algorithm. This 
mode is functional in the 25°C ±  5°C ambient 
temperature range that is required when programming 
the MX27C1100/1024.
To activate this mode, the programming equipment 
must force 12.0 ± 0.5 V on address line A9 of the device. 
Two identifier bytes may then be sequenced from the 
device outputs by toggling address line A0 from VIL to 
VIH. All other address lines must be held at VIL during 
auto identify mode.
Byte 0 ( A0 = VIL) represents the manufacturer code, 
and byte 1 (A0 = VIH), the device identifier code. For the 
MX27C1100/1024, these two identifier bytes are given 
in the Mode Select Table. All identifiers for manufacturer 
and device codes will possess odd parity, with the MSB 
(Q15) defined as the parity bit.
READ MODE
The MX27C1100/1024 has two control functions, both 
of which must be logically satisfied in order to obtain data 
at the outputs. Chip Enable (CE) is the power control 
and should be used for device selection. Output Enable 
(OE) is the output control and should be used to gate 
data to the output pins, independent of device selection. 
Assuming that addresses are stable, address access 
time (tACC) is equal to the delay from CE to output (tCE). 
Data is available at the outputs tOE after the falling edge 
of OE's, assuming that CE has been LOW and 
addresses have been stable for at least tACC - t OE.
WORD-WIDE MODE
With BYTE/VPP at VCC ± 0.2V outputs Q0-7 present 
data Q0-7 and outputs Q8-15 present data Q8-15, after 
CE and OE are appropriately enabled.
FUNCTIONAL DESCRIPTION
THE PROGRAMMING OF THE MX27C1100/1024
When the MX27C1100/1024 is delivered, or it is 
erased, the chip has all 1M bits in the "ONE" or HIGH 
state.  "ZEROs" are loaded into the MX27C1100/1024 
through the procedure of programming.
For programming, the data to be programmed is applied 
with 16 bits in parallel to the data pins.
VCC must be applied simultaneously or before VPP, and 
removed simultaneously or after VPP. When 
programming an MXIC EPROM, a 0.1uF capacitor is 
required across VPP and ground to suppress spurious 
voltage transients which may damage the device.
FAST PROGRAMMING
The device is set up in the fast programming mode when 
the programming voltage VPP = 12.75V is applied, with 
VCC = 6.25 V and PGM = VIL(or OE = VIH) (Algorithm 
is shown in Figure 1). The programming is achieved by 
applying a single TTL low level 100us pulse to the PGM 
input after addresses and data line are stable. If the data 
is not verified, an additional pulse is applied for a 
maximum of 25 pulses. This process is repeated while 
sequencing through each address of the device. When 
the programming mode is completed, the data in all 
address is verified at VCC = VPP = 5V ± 10%.
PROGRAM INHIBIT MODE
Programming of multiple MX27C1100/1024's in parallel 
with different data is also easily accomplished by using 
the Program Inhibit Mode. Except for CE and OE, all like 
inputs of the parallel MX27C1100/1024 may be 
common. A TTL low-level program pulse applied to an 
MX27C1100/1024 CE input with VPP = 12.5 ± 0.5 V will 
program the MX27C1100/1024. A high-level CE input 
inhibits the other MX27C1100/1024s from being 
programmed.
PROGRAM VERIFY MODE
Verification should be performed on the programmed 
bits to determine that they were correctly programmed. 
The verification should be performed with OE and CE at