Texas Instruments Stellaris LM3S9B96, User Manual

Page: 74 / 81

74 September 5, 2010
Hardware Description
The block diagram for the EM2 expansion board is shown in Figure G-7.
Figure G-7. EM2 Expansion Board Block Diagram
Primary EM Header
The primary EM header should always be used when only one EM module is installed unless
otherwise indicated in the README First document for the EM module you are installing.
The primary EM header connects three buses to the EPI connector that are also shared with the
secondary EM header. These buses are I
2
C, UART1, and SPI.
NOTE: The primary and secondary EM headers have a unique SPI chip select signal, but share
the data and clock signals.
The primary EM header contains four GPIO connections to the EPI connector. These GPIOs can
be used as inputs or outputs depending upon the EM module installed. In addition, four unique
GPIOs are provided to each EM header.
EPI
Connector
UART1
MOD1 GPIO
MOD2 GPIO
MOD1 SHUTDOWN
MOD2 SHUTDOWN
SPI
MOD1 SPI_CS
MOD2 SPI_CS
MOD_I2C
AD_I2C
+3.3 V
CAT24C01
EEPROM
32 KHZ
OSC
/4
/4
/4
SDIO
Header
I
2
S
Audio
Header
Analog
Audio
Header
I
2
S
Audio
Header
Analog
Audio
Header
+3. 3 V
I2C
UART
SPI
SHUT
DOWN
GPIO
+3. 3 V
I2C
UART
SPI
SHUT
DOWN
GPIO
SECONDARY
EM
HEADER
(MOD2)
PRIMARY
EM
HEADER
(MOD1)