incdir  "tests"
include "dsp_base.inc"

test_main:

; Test parameters
lri $AC0.M, #0x0000 ; start
lri $AC0.L, #0x0000 ; start
lri $AC1.M, #0x0000 ; end
lri $AC1.L, #0x0011 ; end

; Set the sample format
lri $AC0.H, #0x08 ; 4-bit PCM, gain scaling = x / 2048
sr @0xffd1, $AC0.H
; Set the starting and current address
srs @ACSAH, $AC0.M
srs @ACCAH, $AC0.M
srs @ACSAL, $AC0.L
srs @ACCAL, $AC0.L
; Set the ending address
srs @ACEAH, $AC1.M
srs @ACEAL, $AC1.L

; Set the gains
si @GAIN, #0x0800 ; 2048 / 2048 = 1.0
si @COEF_A1_0, #0x0400 ; 1024 / 2048 = 0.5
si @COEF_A2_0, #0x0200 ; 512 / 2048 = 0.25

; Reset some registers (these must be reset after setting FORMAT)
lri $AC0.H, #0x0000
sr @0xffda, $AC0.H ; pred scale, use 0th coefficients
sr @0xffdb, $AC0.H ; yn1
sr @0xffdc, $AC0.H ; yn2

call load_hw_reg_to_regs
call send_back ; check the accelerator regs before a read

; Expected read sequence
; r[0] = (data[0] >> 4) + (0/2) + (0/4)
; r[1] = (data[0] & 0xf) + (r[0]/2) + (0/4)
; r[2] = (data[1] >> 4) + (r[1]/2) + (r[0]/4)
; r[3] = (data[1] & 0xf) + (r[2]/2) + (r[1]/4)
; ...

bloopi #40, end_of_loop
  lr $IX3, @ACDSAMP
  call load_hw_reg_to_regs
  call send_back ; after a read
  nop ; Loops that end at a return of a call are buggy on hw
end_of_loop:
  nop

jmp end_of_test

load_hw_reg_to_regs:
  lr $AR0, @0xffd1 ; format
  lr $AR1, @0xffd2 ; unknown
  lr $AR2, @0xffda ; pred scale
  lr $AR3, @0xffdb ; yn1
  lr $IX0, @0xffdc ; yn2
  lr $IX1, @0xffdf ; unknown accelerator register

  lri $AC0.H, #0
  lrs $AC0.M, @ACSAH
  lrs $AC0.L, @ACSAL

  lri $AC1.H, #0
  lrs $AC1.M, @ACEAH
  lrs $AC1.L, @ACEAL

  lrs $AX0.H, @ACCAH
  lrs $AX0.L, @ACCAL
  lrs $AX1.H, @ACCAH
  lrs $AX1.L, @ACCAL

  lrs $AX1.H, @ACCAH
  lrs $AX1.L, @ACCAL

  ret