msgsnd

Message Send

msgsnd RB

Sends a doorbell interrupt to another processor.

Details

The instruction sends a message to other threads based on the contents of register RB. The message type and destination thread(s) are specified in RB.

Pseudocode Operation

msgtype ← GPR(RB)32:36
payload ← GPR(RB)37:63
if (msgtype = 0x05)
then
    send_msg(msgtype, payload)

Programming Note

If msgsnd is used to notify the receiver that updates have been made to storage, a sync should be placed between the stores and the msgsnd. See Section 6.9.2.

Example

msgsnd r5

Encoding

Binary Layout
31
0
/
6
/
30
RB
31
206
/
 
Format X-form
Opcode 0x7C00019C
Extension Privileged

Operands

  • RB
    Message Type