Why DC and C flag set when using compare instruction

Question

I use PIC24 for this

;cp{.b} f

mov #0x0003,W1
mov W1,0x0830
mov #0x0002,W0
cp 0x0830  ; DC=1 , N=0 , OV=0, Z=0, C=1 
mov #0x0003,W0
cp 0x0830  ;