konradb
Newbie level 6
- Joined
- May 28, 2009
- Messages
- 13
- Helped
- 2
- Reputation
- 4
- Reaction score
- 0
- Trophy points
- 1,281
- Activity points
- 1,386
I am using a STM32F4 FSMC to address external 16-bit SRAM on a custom board. Everything is OK.
I want to connect an external FPGA and I'm not so clear about the actual addressing.
Please correct me if I'm being stupid, the MCU is 32bit, but the internal AHB address bus is bytewise. The external address bus is 16-bit, so A0 addresses 2 x 16-bit locations.
Therefore to access say
0x00000004 & 0x00000005 A0=1 A1=1 A2=0
0x00000000 & 0x00000001 A0=0 A1=0 A2=0
0x00000002 & 0x00000003 A0=1 A1=0 A2=0
Or is it bytewise
0x00000000 A0=0 A1=0 A2=0
0x00000001 A0=1 A1=0 A2=0
Or is it 32-bit wide as the 16-bit words are read in in 2 cycles
0x00000000 A0=0 A1=0 A2=0
0x00000004 A0=1 A1=0 A2=0
I want to connect an external FPGA and I'm not so clear about the actual addressing.
Please correct me if I'm being stupid, the MCU is 32bit, but the internal AHB address bus is bytewise. The external address bus is 16-bit, so A0 addresses 2 x 16-bit locations.
Therefore to access say
0x00000004 & 0x00000005 A0=1 A1=1 A2=0
0x00000000 & 0x00000001 A0=0 A1=0 A2=0
0x00000002 & 0x00000003 A0=1 A1=0 A2=0
Or is it bytewise
0x00000000 A0=0 A1=0 A2=0
0x00000001 A0=1 A1=0 A2=0
Or is it 32-bit wide as the 16-bit words are read in in 2 cycles
0x00000000 A0=0 A1=0 A2=0
0x00000004 A0=1 A1=0 A2=0
