Command Specifications
(2)Mode = 0, 0, 0, 1: Header + data, without address specification
The format of data transferred from the INIT in this mode must be the same as in the case of Mode = 0, 0, 0, 0, and the
In this mode, the top address of the data buffer where the data transferred from the INIT are stored can be specified in the “Buffer address” field in the CDB.
The “Transfer byte length” field in the CDB specifies the total number of bytes of data transferred by the INIT. The transfer byte count specification includes the 4 bytes of the header. The IDD stores data transferred from the INIT, in a length in which the number of bytes in the header has been deleted from the data (“Transfer byte length” – 4 bytes) in the data buffer beginning at the byte position specified in the “Buffer address” field in the CDB.
Furthermore, a value less than the [“IDD’s buffer size” – value specified in the “Buffer address” field – 4 bytes] must be specified in the “Transfer byte length” field in the CDB. When a value larger than that is specified, data transfer is not executed with the INIT. Also, when zero is specified in the “Transfer byte length” field, this command is terminated without data transfer being executed.
(3)Mode = 0, 0, 1, 0: Data only, with address specification
In this mode, data transfer from the INIT includes buffer data only without the
The top address of the data buffer where the data transferred from the INIT are to be stored can be specified in the “Buffer address” field.
The “Transfer byte length” field in the CDB specifies the total number of bytes of data transferred by the INIT. The IDD stores data transferred from the INIT in the data buffer beginning at the byte position specified in the “Buffer address” field in the CDB.
Furthermore, a value less than the [“IDD’s buffer size” – value specified in the “Buffer address” field] must be specified in the “Transfer byte length” field in the CDB. When a value larger than that is specified, data transfer is not executed with the INIT. Also, when zero is specified in the “Transfer byte length” field, this command is terminated without data transfer being executed.
(4)Mode = 0, 1, 0, 0: Microcode download, without saving
In this mode, the controller’s microcode or control information is transferred to the IDD’s control memory area. “0” must be specified in the “Buffer ID” field and the “Buffer address” field.
The "Transfer byte length" field specifies the total number of transfer bytes of data transferred from the INIT.
When downloading of microcode is completed, the IDD generates a UNIT ATTENTION condition for all the INITs. At this time, the IDD performs microprogram reboot and generates sense code.
The IDD operates according to this microcode until its power is switched off. If the power is switched on again, the IDD’s operation returns to the existing microcode saved previously on the disk.
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