Atmel AT89C51ED2 - Page 20

Appendix C: Board Schematics
4-19 AT89STK-11 Hardware User Guide
7676B–8051–08/07
Figure 4-5. AT89STK-11 Schematics (4 of 4)
DSR
Vcc
RTS Rx_PC CTS
CTS RTS
Tx_MCU
DTR
Tx_PC
Rx_MCU
Vcc
Vcc
Vcc
Vcc
Vcc
Vcc
Vcc
Vcc
P3_0/RxD
P3_1/TxD
/PSEN RST
"grain de café""grain de café"
Vcc
SP4SP4
C26 100n C26 100n
CD2 100n CD2 100n
C16 100n C16 100n
C23 100n C23 100n
SW1 RESET SW1 RESET
R22 1K R22 1K
2 3
14
1
7
U9A
74HC125/SO_5
U9A
74HC125/SO_5
SP3SP3
C21 100n C21 100n
1 2
J11
RTS
J11
RTS
R24 1K R24 1K
C22 100n C22 100n
SW8 ISP SW8 ISP R23 1K R23 1K
C18 100n C18 100n
C17 100n C17 100n
C25 100n C25 100n
5 6
14
4
7
U9B
74HC125/SO_5
U9B
74HC125/SO_5
1 2
J13J13
C20 100n C20 100n
C1+
1
C1-
3
C2+
4
C2-
5
VCC
16
GND
15
V+
2
V-
6
R1OUT
12
R2OUT
9
T1IN
11
T2IN
10
R1IN
13
R2IN
8
T1OUT
14
T2OUT
7
U8
SIPEX-SP3232ECA
U8
SIPEX-SP3232ECA
1 2
J12
DTR
J12
DTR
D11 Green Led Rx LED D11 Green Led Rx LED
R6 10K R6 10K
C24 100n C24 100n
C1+
1
C1-
3
C2+
4
C2-
5
VCC
16
GND
15
V+
2
V-
6
R1OUT
12
R2OUT
9
T1IN
11
T2IN
10
R1IN
13
R2IN
8
T1OUT
14
T2OUT
7
U7 SIPEX-SP3232ECA U7 SIPEX-SP3232ECA
C19 100n C19 100n
5 9 4 8 3 7 2 6 1
P1 SUB-D9 FEMALE RS232 P1 SUB-D9 FEMALE RS232
D12 Green Led Tx LED D12 Green Led Tx LED