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16-13
PROGRAMMING THE NONVOLATILE MEMORY
16.7 ENTERING PROGRAMMING MODES
To execute programs properly, the device must have these minimum hardware connections:
XTAL1 driven, unused input pins strapped, and power and grounds applied. Follow the operating
conditions specified in the datasheet. Place the device into programming mode by applying V
PP
voltage (+12.5 V) to EA# during the rising edge of RESET#.
16.7.1 Selecting the Programming Mode
The PMODE (P0.7:4) value controls the programming mode. PMODE is sampled on the rising
edge of RESET#. You must reset the device to switch programming modes. Table 16-7 lists the
PMODE value for each programming mode. All other PMODE values are reserved.
— EA# I All External Access
Controls program mode entry. If EA# is at V
PP
voltage on the rising edge of RESET#, the device
enters programming mode.
EA# is sampled and latched only on the rising edge
of RESET#. Changing the level of EA# after reset
has no effect.
—V
PP
I All Programming Voltage
During programming, the V
PP
pin is typically at
+12.5V (V
PP
voltage). Exceeding the maximum V
PP
voltage specification can damage the device.
Table 16-7. PMODE Values
PMODE Value
(Hex)
Programming Mode
5 Slave programming
6 ROM-dump
9 UPROM programming (MH only)
C Auto programming
D PCCB programming (MH only)
Table 16-6. Pin Descriptions (Continued)
Port Pin
Special-
function
Signal
Type
Program-
ming
Mode
Description