diff --git a/.vscode/settings.json b/.vscode/settings.json
index df05f40..a06ac45 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -16,6 +16,7 @@
         "dhcp.h": "c",
         "debug.h": "c",
         "systick.h": "c",
-        "timer.h": "c"
+        "timer.h": "c",
+        "stdint.h": "c"
     }
 }
\ No newline at end of file
diff --git a/README.md b/README.md
index 4e01787..46aec66 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,19 @@
 # ch32-node fw
 fw for a ch32v203 node w/ w5500 ethernet
 
-## current pain
+## current
 
 ### SysTick IRQ and DMA issue
-Enabling the SysTick IRQ leads to a permanent hang of the socket.
-  - With a 1ms interval, the hang occurs at `DHCP_ACK` during the `check_DHCP_leasedIP` -> `sendto()` ARP request.
-  - With a 1s interval, the hang occurs during the DNS request.
-  - Disabling SPI DMA solves it (just commenting out `reg_wizchip_spiburst_cbfunc`), so it's most likely DMA related?
-  - SPI DMA only works at SPI baud @ 8 or 64??
+[Enabling](https://git.hye.su/mira/ch32-node/src/branch/master/src/main.c#L54) the SysTick IRQ leads to a permanent hang of the socket.
+  - With a 1ms IRQ interval, the hang occurs at `DHCP_ACK` during the `check_DHCP_leasedIP` -> `sendto()` [ARP request](https://git.hye.su/mira/ch32-node/src/branch/master/lib/ioLibrary_Driver/socket.c#L563).
+  - With a 100ms interval, the hang occurs during the DNS request.
+  - With a 1s interval it works
+  - [Disabling SPI DMA](https://git.hye.su/mira/ch32-node/src/branch/master/src/w5500.c#L62) solves it (just commenting out `reg_wizchip_spiburst_cbfunc`), so it's most likely DMA related?
+  - SPI DMA only works with [prescalers](https://git.hye.su/mira/ch32-node/src/branch/master/src/spi_dma.c#L140) 8 and 64?
 
+TODO: LA?...
 
-## ~~previous pain (DNS Processing)~~
+## ~~previous (DNS Processing)~~
 solved by [patching](https://git.hye.su/mira/ch32-node/commit/259d63197e06c1a92b979490d4cd8f0fdb98f8d0#diff-6ba50689ba55dac7cfe3e9b011e594098c931e21) the korean bloatlib (`dns_makequery` in DNS.c)
 
 w/ ch32v003fun
diff --git a/src/main.c b/src/main.c
index 01aa937..1e75545 100644
--- a/src/main.c
+++ b/src/main.c
@@ -51,7 +51,6 @@ int main(void) {
   // TODO: enabling any kind of SysTick IRQ literally causes the socket to hang forever
   // with 1ms interval the hang is on DHCP_ACK, on check_DHCP_leasedIP -> sendto() ARP req
   // with 1s it happens somewhere on DNS req
-  // wtf?
   init_systick();
   tim2_init();