
|
|
| Industrial Temperature Rated USB 2.0 |
|
|
| Datasheet |
| Table 3.1 USB2512Ai Pin Descriptions (continued) | ||
|
|
|
|
| BUFFER |
| |
SYMBOL | EMB | TYPE | DESCRIPTION |
|
|
|
|
XTAL2 | 32 | OCLKx | Crystal Output |
|
|
| 24MHz Crystal |
|
|
| This is the other terminal of the crystal, or a NO CONNECT |
|
|
| when an external clock source is used to drive XTAL1/CLKIN. |
|
|
| Note: This output must not be used to drive any external |
|
|
| circuitry other than the crystal circuit. |
|
|
|
|
RESET_N | 26 | IS | RESET Input |
|
|
| The system can reset the chip by driving this input low. The |
|
|
| minimum active low pulse is 1 μs. |
|
|
| When the RESET_N pin is pulled to VDD33, the internal POR |
|
|
| |
|
|
| required. The internal POR holds the internal logic in reset until |
|
|
| the power supplies are stable. |
|
|
|
|
SUSP_IND/ | 28 | I/O | Active/Suspend status LED or |
LOCAL_PWR/ |
|
| Strap Option |
NON_REM0 |
|
| Suspend Indicator: Indicates USB state of the Hub. |
|
|
| |
|
|
| ‘negated’ = Unconfigured, or configured and in USB Suspend |
|
|
| ‘asserted’ = Hub is configured, and is active (i.e., not in |
|
|
| suspend) |
|
|
|
|
|
|
| Local Power: Detects availability of local |
|
|
| Low = Self/local power source is NOT available (i.e., Hub gets |
|
|
| all power from Upstream USB VBus). |
|
|
| High = Self/local power source is available. |
|
|
| NON_REM0 Strap Option: |
|
|
| If this strap is enabled by package and configuration settings |
|
|
| (see Table 3.2, "SMBus or EEPROM Interface Behavior"), this |
|
|
| pin will be sampled (in conjunction with NON_REM1) at |
|
|
| RESET_N negation to determine if ports [2:1] contain |
|
|
| permanently attached |
|
|
| active state of the LED will be determined as follows: |
|
|
| NON_REM[1:0] = ‘00’, All ports are removable, and the LED is |
|
|
| active high |
|
|
| NON_REM[1:0] = ‘01’, Port 1 is |
|
|
| is active low |
|
|
| NON_REM[1:0] = ‘10’, Ports 1 & 2 are |
|
|
| LED is active high |
|
|
| NON_REM[1:0] = ‘11’, Ports 1 & 2 are |
|
|
| LED is active low |
|
|
|
|
TEST | 11 | IPD | TEST pin |
|
|
| XNOR continuity tests all signal pins on the Hub. Please |
|
|
| contact your SMSC representative for a detailed description of |
|
|
| how this test mode is enabled and utilized. |
|
|
|
|
Revision 1.97 | 10 | SMSC USB2512Ai |
| DATASHEET |
|