AN1921 Motorola / Freescale Semiconductor, AN1921 Datasheet - Page 7

• Manufacturer Part Number: AN1921
• Description: AN1921 General DSP568xx Interface Examples using the Embedded SDK
• Manufacturer: Motorola / Freescale Semiconductor

3.
A polling loop is executed which takes input from the keypad and displays the value passed to the
program in the printf() text window. When the user enters a string and presses the E [Enter] key, the
string is displayed in the IDE’s text window. After entering values, the user exits the loop by entering
“0000”, followed by [Enter]. The display will clear and the string “Done!” will appear.
The previous section described the LCD/keypad interface and operation from the SPI1 port via the
MAX3100 UART. The connection to the UART and, in turn, the EVM’s RS-232 serial port was
established, with the default jumpers left in place at the EVM’s J2 header. The DSP’s SPI0 is
interfaced to a serial EEPROM via the jumpers left in place on the J1 header. Removing the jumpers
and connecting wires to pins 1,3,5, and 7 permits the user to directly interface another SPI device to the
DSP; see
Interfacing to Serial Devices Using the SPI Port
Table 2: Signal Description at J1 Header between SPI0 and EEPROM
Table
2.
Pin #
1
3
5
7
9
Figure 4. Keypad’s Key Assignment Values
Interface Examples Using the Embedded SDK
Cable to LCD
DSP Signal
MISO1/PC0
MOSI1/PC1
SCK1/PC2
SS1/PC3
GND
J1
D
4
7
1
Pin #
10
2
4
6
8
Interfacing to Serial Devices Using the SPI Port
2
5
8
0
H
3
6
9
EEPROM Signal
B
C
A
GND
E
SCK
SD1
SD0
CS
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