[Sdcc-user] 4x memory usage on mcs51 (sdcc 2.9.0)

[Eric A. <eri...@sh...>]

I have an in- and out-buffer of 64 bytes that should fit in the near ram, but it gets a linker error of:
	link-Error-Could not get 128 consecutive bytes in internal RAM for area ISEG.

Declaration:
	__idata BYTE Out_Packet[64];             // Last packet received from host
	__idata BYTE In_Packet[64];              // Next packet to sent to host

Linker map shows:
	Area                               Addr   Size   Decimal Bytes (Attributes)
	--------------------------------   ----   ----   ------- ----- ------------
	ISEG                               0000   0200 =    512. bytes (REL,CON)

	      Value  Global
	   --------  --------------------------------
	     0100    G$Out_Packet$0$0
	     0100    _Out_Packet
	     0140    G$In_Packet$0$0
	     0140    _In_Packet

BYTE is type defined as unsigned char but appears to use 4 bytes per element. I tried changing them to int and long long, both of which seem to take up 4 times what they should (8 bytes per int, 16 per long). What am I missing here?

Attached: mem layout.