add developer documentation to ppusim/ppu interface

1 files changed, 6 insertions, 0 deletions

diff --git a/src/ppu/internals.h b/src/ppu/internals.h
index 8f50c52..4a1726e 100644
--- a/src/ppu/internals.h
+++ b/src/ppu/internals.h
@@ -9,6 +9,7 @@
 /** @brief resize `in` to `upper downto lower` like in vhdl */
 #define HH_RESIZE(in, upper, lower) ((((hh_ppu_data_t)(in)) & (HH_MASK(upper+1-lower) << lower)) >> lower)
 
+/** @brief memory word(s) that can be placed into vram */
 typedef struct {
 	hh_ppu_addr_t offset;
 	hh_ppu_addr_t size;
@@ -22,9 +23,14 @@ void hh_ppu_vram_dwrite(hh_ppu_addr_t addr, hh_ppu_data_t data);
 /** @brief write data block into vram */
 void hh_ppu_vram_write(hh_s_ppu_vram_data data);
 
+/** @brief convert local background attribute memory entry to PPU format */
 hh_s_ppu_vram_data hh_ppu_2nat_bam(hh_s_ppu_loc_bam_entry);
+/** @brief convert local foreground attribute memory entry to PPU format */
 hh_s_ppu_vram_data hh_ppu_2nat_fam(hh_s_ppu_loc_fam_entry);
+/** @brief convert local AUX memory copy to PPU format */
 hh_s_ppu_vram_data hh_ppu_2nat_aux(hh_s_ppu_loc_aux);
+/** @brief convert local sprite to PPU format */
 hh_s_ppu_vram_data hh_ppu_2nat_sprite(const hh_ppu_loc_sprite_data_t);
+/** @brief convert local RGB color to PPU format */
 hh_s_ppu_vram_data hh_ppu_2nat_color(hh_ppu_rgb_color_t);