DLPU048E August 2016 – July 2024
This command is used to read the short status from hardware. This is the only read command that does not require the use of Read Pre-Fetch and Read Activate commands. Refer to Section 3.5 for more information on the Short Status protocol.
Command Parameters
No command parameters.
Return Parameters
BYTE | BITS | DESCRIPTION |
---|---|---|
1 | 7:6 | Application / Mode 0x0: Boot application 0x1: Main application - Standby 0x2: Main application - Display |
5 | Emergency Shutdown 0x0: Not activated 0x1: Activated | |
4 | Reserved | |
3 | Read Data Available 0x0: No data available 0x1: Data available | |
2 | System Busy 0x0: Not busy 0x1: Busy | |
1 | Request in Progress 0x0: Not in progress 0x1: In progress | |
0 | System Initialized 0x0: Not initialized 0x1: Initialized | |
2 | 7:0 | Execution Command Tag |
4:3 | 15 | BIST Error 0x0: No error 0x1: Error |
14 | Operational Error 0x0: No error 0x1: Error | |
13 | Command Error 0x0: No error 0x1: Error | |
12 | Communication Error 0x0: No error 0x1: Error | |
11:0 | CMD/COMM Error Code |
A diagram of these short status bits is shown in Figure 7-1.
The bits are described in Table 7-9.
BIT FIELD | DEFINITION |
---|---|
System Initialized | Indicates that the system software is ready to accept commands for processing. Typically this would be set by the Main Application, except when the system is forced to stay in boot. |
Request in Progress | This bit is used to inform the host that a commanded task is being performed. When the task is initiated, this bit will be set to 1 and when the operation has completed the bit will be cleared to 0. If the task was a BIST, the results for the requested test will be valid once the bit has been cleared by embedded software. Further requests can be started after this. |
System Busy | This bit is used to inform the host that the system's receive FIFO is full. The host should not send any more commands when the system is busy, or the commands and associated data may be lost. The Host is free to send commands when the system is not busy. |
Read Data Available | Indicates when read data is available after the host has sent a Read Prefetch command. When data is available, the Host should send the Read Activate command to fetch the requested data. The Host should always fetch requested data using the Read Activate command before sending another Read Prefetch command. If a Read Prefetch command is sent before the data from a previous Read Prefetch command has been fetched, the previous data will be flushed, and the latest requested data will be made available for fetching by Read Activate. There will be no error indication that this has occurred. |
Emergency Shutdown | This bit is used to indicate that the system has automatically gone to Standby Mode due to a critical system error. The specifics of the error may be available via the Error History. |
Application/Mode | These bits indicate whether the boot application or main application is being executed. During main application execution, the current operating mode is also specified. |
Execution Command Tag | This byte contains the command tag for the last write command received that has been executed, whether successful or not. This tag is used along with the Error Code to determine if the command associated with this tag was executed successfully or not. This byte is continually updated as new commands are received and executed.
In the Boot Application, this byte is also used for any system errors. For errors where the command tag is valid, the actual tag will be used. For errors where there is no command tag or the command tag may be invalid, a null (0h) command tag will be provide in this field. In both cases, the appropriate error code will be provided in the error code field. |
Error Code | The 12-bit error code is used to specify the last error received during system operation. The error code can indicate no error (error code = 0h), or indicate the error code for the most recent error to occur. This error code is continually updated as new errors occur. The Error History command can be used to obtain details about previous errors.
For any communication errors, the error code for this error will also be provided in this field. |
Communication Error | A flag set to indicate a communication error, which is used to indicate a problem with the transmission/reception of a command. Some examples are:
|
Command Error | A flag set to indicate a command error, or an error in the action requested by the command. Some examples are:
|
Operational Error | A flag set to indicate an operational error, which are any errors that don't fall into one of the other three error categories. Some examples are:
|
BIST Error | A flag set to indicate a non-periodic or periodic BIST error. |