AT89C51
Figure 3. Programming the Flash
AT89C51
Figure 4. Verifying the Flash
+5V
+5V
AT89C51
A0 - A7
OOOOH/OFFFH
A8 - A11
A0 - A7
OOOOH/0FFFH
A8 - A11
VCC
P0
VCC
P0
ADDR.
P1
ADDR.
P1
PGM DATA
(USE 10K
PULLUPS)
PGM
DATA
P2.0 - P2.3
P2.6
P2.0 - P2.3
P2.6
P2.7
ALE
EA
SEE FLASH
PROGRAMMING
MODES TABLE
SEE FLASH
PROGRAMMING
MODES TABLE
P2.7
ALE
EA
PROG
P3.6
P3.6
VIH
P3.7
P3.7
XTAL2
VIH/VPP
XTAL2
3-24 MHz
3-24 MHz
VIH
XTAL1
GND
RST
VIH
XTAL1
GND
RST
PSEN
PSEN
Flash Programming and Verification Characteristics
TA = 0°C to 70°C, VCC = 5.0 ± 10%
Symbol
Parameter
Min
Max
12.5
1.0
Units
V
(1)
VPP
Programming Enable Voltage
Programming Enable Current
Oscillator Frequency
11.5
(1)
IPP
mA
1/tCLCL
tAVGL
3
24
MHz
Address Setup to PROG Low
Address Hold After PROG
Data Setup to PROG Low
Data Hold After PROG
P2.7 (ENABLE) High to VPP
VPP Setup to PROG Low
VPP Hold After PROG
PROG Width
48tCLCL
48tCLCL
48tCLCL
48tCLCL
48tCLCL
10
tGHAX
tDVGL
tGHDX
tEHSH
tSHGL
µs
µs
µs
(1)
tGHSL
10
tGLGH
tAVQV
tELQV
tEHQZ
tGHBL
tWC
1
110
Address to Data Valid
ENABLE Low to Data Valid
Data Float After ENABLE
PROG High to BUSY Low
Byte Write Cycle Time
48tCLCL
48tCLCL
48tCLCL
1.0
0
µs
2.0
ms
Note: 1. Only used in 12-volt programming mode.
4-35
ATMEL [ ATMEL ]
