In this section, some pins of this device
are referenced by signal names describing their functionality during parallel programming.
Refer to the figure Parallel Programming and to the table Pin Name Mapping
below. Pins not described in the following table are referenced by pin names.
The XA1/XA0 pins determine the action
executed when the XTAL1 pin is given a positive pulse. The bit coding is shown in the table
XA1 and XA0 Coding below.
When pulsing WR or
OE, the command loaded determines the action executed. The
different commands are shown in the table Command Byte Bit Coding below.
Table 33-12. Pin Name Mapping
Signal Name in Programming Mode
Pin Name
I/O
Function
RDY/BSY
PD1
O
0: Device is busy programming, 1: Device is ready for new command
Table 33-13. Pin Values Used to Enter Programming Mode
Pin
Symbol
Value
PAGEL
Prog_enable[3]
0
XA1
Prog_enable[2]
0
XA0
Prog_enable[1]
0
BS1
Prog_enable[0]
0
Table 33-14. XA1 and XA0 Coding
XA1
XA0
Action when XTAL1 is Pulsed
0
0
Load Flash or EEPROM Address (High or low address byte determined by BS1)
0
1
Load Data (High or Low data byte for Flash determined by BS1)
1
0
Load Command
1
1
No Action, Idle
Table 33-15. Command Byte Bit Coding
Command Byte
Command Executed
1000 0000
Chip Erase
0100 0000
Write Fuse bits
0010 0000
Write Lock bits
0001 0000
Write Flash
0001 0001
Write EEPROM
0000 1000
Read Signature Bytes and Calibration byte
0000 0100
Read Fuse and Lock bits
0000 0010
Read Flash
0000 0011
Read EEPROM
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