Write data 0 7 Address Write Op (0x1) 4 3 Footer (0x0) 0 7 Address (0x0-0x7) Write Op (0x1) 4 3 0 7 Address Read Op (0x0) 4 3 Footer (0x0) 0 7 Address (0x0-0x7) Read Op (0x0) 4 3 Read data Footer (0x1) 0 7 Address (0x8-0xF) Read Op (0x0) 4 3 Footer (0x1) 0 7 Address (0x8-0xF) Write Op (0x1) 4 3 Write request Read request Write ack (okay) Write ack (error) Read ack (okay) Read ack (error)