Long description

The 3 lines of code for figure (a) are as follows.

copy underscore from underscore user open parenthesis buffer comma p comma count close parenthesis semicolon

set underscore up underscore DMA underscore controller open close parenthesis semicolon

scheduler open close parenthesis semicolon

The 3 lines of code for figure (b) are as follows

acknowledge underscore interrupt open close parenthesis colon

unblock underscore user open close parenthesis semicolon

return underscore from underscore interrupt open close parenthesis semicolon