Atmel STK526, Руководство пользователя, Страница: 15 / 38

Using the STK526
STK526 rev. B Hardware User Guide 2-15
7709B–AVR–05/07
The STK526 USART implementation allows an optional hardware flow control that can
be enabled thanks to SP1, SP2, SP3, SP4 solder pads (See Figure 2-11).
Figure 2-11 . USART Schematic
Note that the
AT90USB82/162 integrates the Hardware Flow Control in its USART
peripheral without special management by firmware (except init).
Table 2-3 . UART Settings
Note: 1. Tx reference: STK526 source, Rx reference: STK526 destination
Mode
Solder Pads
Configuration
DB9
Connection
(1)
Software Data Flow
Control
(default configuration)
SP4: open
SP5: open
SP7: open
SP8: open
Tx
Rx
Pin 2
Pin 3
Optional
Hardware Flow Control
SP4: close
SP5: close
SP7: close
SP8: close
Tx
Rx
CTS
RTS
Pin 2
Pin 3
Pin 7
Pin 8
5
9
4
8
3
7
2
6
1
10
11
P1
SUB-D9 FEMALE
RS232
RS232 Interface
RS-CT S
VCC
CT S
RT S
.
11
.
12
.
10
.
9
.
8
.
7
.
13
.
14
.
1
5
.
1
6
C1+
1
V+
2
C1-
3
C2+
4
C2-
5
V-
6
RS 232 TTL
GND
VCC
U5
MAX3232
RS232 BUFFER
C14
100nF
C13
100nF
C15
100nF
C17
100nF
RxD PD2
RS-T xD RS-T xD RS-T xD RS-T xD RS-T xD RS-T xD RS-T xD RS-T xD
RS-RxD
PD[7..0]
SP1
SP3
PD7
PD6
PD3 T XD
SP2
SP4
RS-RT S