Mux configuration
From IGEP - ISEE Wiki
Contents
Overview
Mux (or multiplexer) is a Omap peripheral that can be controlled via software. Its function is connect other peripherals to some available Omap pads.
IgepV2 Board have a default mux configuration, but some cases is necessary change it, for example your project need UART2 at j990 connector to transmit data, for this purpose you need change some mux configurations to enable it and be sure that this modification don't break or interferes in other IC or peripherals. The mux options are vast.
This How-To is meant to be a starting point for people to learn configure mux for IGEP v2 devices as quickly and easily as possible. For this how-to i used Linaro Headless and Ubuntu 10.04 with Linaro Toolchain.
Feedback and Contributing
At any point, if you see a mistake you can contribute to this How-To.
Available peripherals on external connector
Before configure mux is necessary review some things:
- If connector is shared with other peripherals you should disable it via software or hardware.
- Don't use the same peripheral in more than one pad.
The next tables show you all the mux capabilities:
J990 connector
-There are some peripherals than can be connected to J990 like mm3 and camera, but is not used in this how-to.
-High Speed USB 3 is only available on Omap 3530 in the next pads:
3: HSUSB3_TLL_NXT
4: HSUSB3_TLL_D4
5: HSUSB3_TLL_DIR
6: HSUSB3_TLL_D6
7: HSUSB3_TLL_STP
8: HSUSB3_TLL_D7
10: HSUSB3_TLL_D5
| Pad: | Connect to: |
Default peripheral (mode=0) |
Default function: | Other available peripherals: | Share with: |
| 1 | VIO 1V8 | - | Power 1v8 | - | - |
| 2 | DC 5V | - | Power 5v | - | - |
| 3 | MMC2_DAT7 | MMC2_DAT7 | Reset Wlan |
MMC2_CLKIN(mode=1) MMC3_DAT3(mode=3) GPIO_139(mode=4) |
Wlan: This pad can reset Wlan peripheral using Omap GPIO low level (GND). If you reset continuously Wlan all their pads are in High Impedance. Also you can disable Wlan from J990 low level. Omap: protect Omap pad if you don't use it.(1)
|
| 5 | MMC2_DAT6 | MMC2_DAT6 | Power down Wlan |
MMC2_DIR_CMD(mode=1) MMC3_DAT2(mode=3) GPIO_138(mode=4) |
Wlan: This pad can power down Wlan peripheral using Omap GPIO low level (GND), power up removing GND. Also you can power down Wlan from J990 low level. Omap: protect Omap pad if you don't use it.(1)
|
| 7 | MMC2_DAT5 | MMC2_DAT5 | Reset Bluethoot |
MMC2_DIR_DAT1(mode=1) MMC3_DAT1(mode=3) GPIO_137(mode=4) |
Bluethoot: This pad can reset Bluethoot
peripheral using Omap GPIO low level (GND). If you reset continuously Bluethoot all their pads are in High Impedance. Also you can disable Bluethoot from J990 low level.Omap: protect Omap pad if you don't use it.(1) |
| 9 | MMC2_DAT4 | MMC2_DAT4 | - |
MMC_DIR_DAT0(mode=1) MMC3_DAT0(mode=3) GPIO136(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 11 | MMC2_DAT3 | MMC2_DAT3 | Transfer data between Omap and Wlan |
McSPI3_CS0(mode=1) GPIO_135(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 13 | MMC2_DAT2 | MMC2_DAT2 | Transfer data between Omap and Wlan |
McSPI3_CS1(mode=1) GPIO_134(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 15 | MMC2_DAT1 | MMC2_DAT1 | Transfer data between Omap and Wlan | GPIO_133(mode=4) | Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 17 | MMC2_DAT0 | MMC2_DAT0 | Transfer data between Omap and Wlan |
McSPI3_SOMI(mode=1) GPIO_132(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 19 | MMC2_CMD | MMC2_CMD | Control Wire for bus MMC2 (Wlan) |
McSPI3_SIMO(mode=1) GPIO_131(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 21 | MMC2_CLK0 | MMC2_CLK | Clock for MMC2 (Wlan) |
McSPI3_CLK(mode=1) GPIO_130(mode=4) |
Wlan: Protect Wlan if you don' use it. See MMC2_DAT7 pad. Omap: protect Omap pad if you don't use it.(1)
|
| 4 | MCBSP3_DX | MCBSP3_DX | Transmitted serial Data (Bluethoot audio) |
UART2_CTS(mode=1) GPIO_140(mode=4) |
TPS65950: disable it via kernel (2) If you don't use it.
|
| 6 | MCBSP3_CLKX | MCBSP3_CLKX | Transmitted serial Clock (Bluethoot audio) |
UART2_TX(mode=1) GPIO_142(mode=4) |
Bluethoot: Protect Bluethoot if you don' use it. See MMC2_DAT5 pad. TPS65950: disable it via kernel (2) If you don't use it.
|
| 8 | MCBSP3_FSX | MCBSP3_FSX | Transmited Frame Syncronisation (Bluethoot audio) |
UART2_RX(mode=1) GPIO_143(mode=4) |
Bluethoot: Protect Bluethoot if you don' use it. See MMC2_DAT5 pad. TPS65950: disable it via kernel (2) If you don't use it.
|
| 10 | MCBSP3_DR | MCBSP3_DR | Received Serial Data (Bluethoot audio) |
UART2_RTS(mode=1) GPIO_141(mode=4) |
TPS65950: disable it via kernel (2) If you don't use it.
|
| 12 | MCBSP1_DX | MCBSP1_DX | Transmited serial Data (not used) |
McSPI4_SIMO(mode=1) McBSP3_DX(mode=2) GPIO_158(mode=4) |
- |
| 14 | MCBSP1_CLKX | MCBSP1_CLKX | Transmited serial clock (not used) |
McBSP3_CLKX(mode=2) GPIO_162(mode=4) |
- |
| 16 | MCBSP1_FSX | MCBSP1_FSX | Transmited Frame Syncronization (not used) |
McSPI4_CS0(mode=1) McBSP3_FSX(mode=2) GPIO_161(mode=4) |
- |
| 18 | MCBSP1_DR | MCBSP1_DR | Received Serial Data (not used) |
McSPI4_SOMI(mode=1) McBSP3_DR(mode=2) GPIO_159(mode=4) |
- |
| 20 | MCBSP1_CLKR | MCBSP1_CLKR | Received Clock (not used) |
GPIO_156(mode=4) |
- |
| 22 | MCBSP1_FSR | MCBSP1_FSR | Received frame syncronization (not used) |
GPIO_157(mode=4) |
- |
| 23 | I2C2_SDA | I2C2_SDA | I2C Data |
GPIO_183(mode=4) |
Cam connector: Check and RC14 is not welded or don't use it.
|
| 24 | I2C2_SCL | I2C2_SCL | I2C Clock |
GPIO_168(mode=4) |
Cam connector: Check and RC13 is not welded or don't use it. |
| 25 | REGEN | - | Master/Slave control power TPS65950 |
- | - |
| 26 | nRESET | - | Read Reset Omap | - | - |
| 27 | GND | - | GND | - | - |
| 28 | GND | - | GND | - | - |
(1): To protect Omap pads from esternal signals configure Mux in mode=7 (safe_mode). With this mode, buffer is configured in high impedance
(2): Disable TPS65950 go to file sound/soc/codecs/twl4030.c change line 54 Code:
0x00, /* REG_VOICE_IF (0xF) */
to Code:
0x04, /* REG_VOICE_IF (0xF) */
(3): Omap mux have 8 modes, somes modes are disable in some pads.
J960 connector
J960 connector can not use mux capabilities, because this connector is dedicated to use RS232 comunication. Default hardware/software configuration is:
| Pad | Connect to: | Default periphera: | Other peripheral: | Share with: |
Default function: |
| 1 | - | - | - | - |
|
| 2 | RS232_RX2 | UART3_RX | UART2_RX | - |
Kernel console params(4) |
| 3 | RS232_TX2 | UART3_TX | UART2_TX | - |
Kernel console params(4) |
| 4 | - | - | - | - |
- |
| 5 | GND | - | - | - |
- |
| 6 | GND | - | - | - |
- |
| 7 | - | - | - | - |
- |
| 8 | RS232_TX1 | UART1_TX | UART3_TX | RS485 interface(5) |
- |
| 9 | RS232_RX1 | UART1_RX | UART3_RX | RS485 interface(5) |
- |
| 10 | - | - | - | - |
- |
- Don't use the same peripheral in more than one pad.
- Other peripherals can be configured via hardware, placing/replacing some resistances. See IGEPv2 Schematic for more information.
(4): To set other functionalities to UART3 (/dev/ttyS2) edit igep.ini file:
Search line:
console=ttyS2,115200n8
Replace by:
; console=ttyS2,115200n8
(5): Allows to use UART1 as RS232 instead of EI485, edit igep.ini:
Search line:
board.ei485=yes
Replace by:
board.ei485=no
J400 connector
J400 is used to JTAG (Joint Test Action Group). JTAG is a standardized serial protocol widely used in printed circuit boards.Its main functions are:
-Debug the software of an embedded system directly
-Storing firmware
-Boundary scan testing
More information: http://es.wikipedia.org/wiki/JTAG.
Only Pad 13 and 14 have mux capabilities, for example you can use them like GPIO.
