Fujitsu MBA3147RC, MBC2036RC, MBC2073RC, MBA3300RC Mode = 1, 0, 1, 1 Echo buffer descriptor, Ebos

Command Specifications

(6) Mode = 1, 0, 1, 1 : Echo buffer descriptor

In this mode, a maximum of four bytes of READ BUFFER descriptor information is returned. The device server shall return the descriptor information for the echo buffer. The "Buffer Offset" field is reserved in this mode. The allocation length should be set to four or greater. The device server shall transfer the lesser of the allocation length or four bytes of READ BUFFER descriptor. The READ BUFFER descriptor is defined as shown in Table 4.65.

Table 4.65 READ BUFFER command: echo buffer descriptor

	Bit	7	6	5	4		3	2	1	0
Byte
	0				Reserved					EBOS
	1				Reserved
	2		Reserved			Echo Buffer Capacity (MSB)
	3			Echo Buffer Capacity (LSB)

The HDD return one in EBOS field, and the HDD verifies that echo buffer data from each initiator is the same as that previously written by the same initiator.

The "Buffer Capacity" field returns the size of the echo buffer X'0400' in bytes aligned to a four-byte boundary.

274 C141-C013