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User’s Guide 21020285 D
Chapter 4 Command Operation
Example ‘C’ Routines for Command List Page 4 - 23
Example ‘C’
Routines for
Command List
The following ‘C’ listing is included here as an example of how you may set-
up the Parameter Block, Status Block and Command List structures and
manipulate the Command List Indexes.
/* Global Defines: */
#define EMPTY 0
#define NPB 100 /* NPB - Num of Parameter Blocks in Command List. */
#define NSB 200 /* NSB - Num of Status Blocks in Command List. */
#define BYTE unsigned char /* an 8 bit value */
#define WORD unsigned int /* a 16 bit value */
#define DWORD unsigned long /* a 32 bit value */
/* parameter_block - a structure used to pass a command to the RF3880 VME to
* SCSI adapter. The fields are:
*/
typedef struct
{
DWORD identifier; /* identifier - command identifier. */
BYTE flags-2; /* command flags. */
BYTE flags-1; /* command flags. */
BYTE modifier; /* modifier - address modifier. */
BYTE target; /* target - target ID or adpater ID. */
/* possible values for flags-1 */
#defineCF_VALID 0x80 /* dat and dir bits valid. */
#defineCF_FREE 0x40 /* reserved bit, not used. */
#defineCF_INHIBIT_CMD_COMPLETE0x20 /* command list, synch control. */
#defineCF_FREE1 0x10 /* reserved bit, not used.*/
#defineCF_IRS 0x08 /* inhibit request-sense. */
#defineCF_DATA 0x04 /* data for this opration. */
#defineCF_DIR 0x02 /* direction; 1 = (writes). */
/* possible values for flags-2 */
#defineCF_JUST_SEND_MSG 0x08 /* message-only operation. */
#defineCF_INHIBIT_DISCONNECT 0x04 /* inhibit disconnect. */
#defineCF_TAG_MESSAGE_TYPE 0x02 /* tag message type. */
union
{
WORD w[2];
DWORD d;
} sdp; /* sdp - source/dest. memory address */
union
{
WORD w[2];
DWORD d;
} bytes; /* bytes - data transfer count */