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DSH_BT024-00200_1v4 © Ezurio Ltd 2006
4
3.2
Pin Descriptions
The table below defines the pin functions. Refer to the previous section for the pin location
Pin
No.
Signal
Description
Pin
No.
Signal
Description
1
VCC
2
USB /RESERVED
Do not connect
3
USB /RESERVED
Do not connect
4
GND
5
RESET-
Reset I/P *
6
GPIO_6
I/O for Host
7
GPIO_7
I/O for Host
8-19
N/C
Do not Connect
20
GND
21
UART_DCD
I/O for Host
22
UART_RI
I/O for Host
23
UART_RTS
Request to Send O/P
24
UART_RX
Receive Data I/P
25
UART_CTS
Clear to Send I/P
26
UART_TX
Transmit Data O/P
27
UART_DTR
(GPIO_3)
I/O for Host
28
UART_DSR
Input
29
GND
30
PCM_SYNC
PCM Sync I/P
31
PCM_IN
PCM Data I/P
32
PCM_CLK
PCM Clock I/P
33
PCM_OUT
PCM Data O/P
34
GPIO_9
PCM_SLVCLK
I/O for Host (Slave
PCM Clock)
35
GPIO_5
I/O for Host (LED2)
36
GPIO_4
I/O for Host (LED1)
37
Analogue_0
ADC
38
GPIO_8
I/O for Host
39-42
N/C
Do not connect
Notes:
* The reset line has a fixed 10kOhm pull up resistor with the reset being active low.
PIO lines can be configured through software to be either inputs or outputs with weak or strong pull-ups or pull-
downs. At reset, all PIO lines are configured as inputs with weak pull-downs.
UART_RX, UART_TX, UART_CTS, UART_RTS, UART_RI, UART_DCD and UART_DSR are all 3.0v level logic. For
example, when RX and TX are idle they will be sitting at 3.0V. Conversely for handshaking pins CTS, RTS, RI,
DCD, DSR a 0v is treated as an assertion.
Pin 22 (UART_RI) is active low. It is normally 3.0v. When a remote device initiates a connection, this pin goes
low. This means that when this pin is converted to RS232 voltage levels it will have the correct voltage level for
assertion.
Pin 21 (UART_DCD) is active low. It is normally 3.0v. When a connection is live this pin is low. This means that
when this pin is converted to RS232 voltage levels it will have the correct voltage level for assertion.
Pin 28 (UART_DSR) is an input, with active low logic. It should be connected to the DTR output of the host. When
the Module is in high speed mode (See definition for S Register 507), this pin should be asserted by the host to
ensure that the connection is maintained. A deassertion is taken to mean that the connection should be dropped,
or an online command mode is being requested.
The GPIO pins can be accessed using S Registers in the range 623 to 629. GPIO4 and 5 are connected to
unpopulated LED pads on the module. If these I/O pins are set for input, then the LED will be driven by the host
and appropriate drive current requirements must be satisfied. A Logic 1 switches on the LED.
GPIO3 is shares the pin with DTR output (active low). See S Register 552 & 553.
Analogue 0 input should not exceed 1.8v. S Register 701 is used to access it.