oh/mio

Mini-IO: A lightweight parallel interface

Introduction

• Mini-IO (MIO) is a generic protocol agnostic link for moving data between chips (or silicon dies).

Key Features

• Dual data rate data transfers
• Source synchronous
• Clock aligned by transmitter at 90 degrees
• Parametrized I/O and system side bus width
• Data transmitted MSB first

Protocol

Interface

SIGNAL	DIR	DESCRIPTION
access_in	I	Valid packet for TX
data_in	I	Data for TX
wait_out	O	Pushback from TX towards core side
access_out	I	Valid packet from RX
data_out	I	Data from RX
wait_in	O	Pushback for RX from core side
tx_access	O	TX packet framing signal
tx_clk	O	TX clock aligned in the center of the data eye
tx_data	I	TX DDR data
tx_wait	I	TX pushback from RX
rx_access	I	RX packet framing signal
rx_clk	I	RX center aligned clock
rx_data	I	RX DDR data
rx_wait	O	RX pushback for TX
clk	I	Core side clock
nreset	I	Active low async reset
io_clk	I	Clock for transmit side
datasize	I	Size of data to transmit (<PW)
divcfg[3:0]	I	Divider setting for TX clock divider

Top level file

• c2c.v

Parameters

• `CFG_MIOPW : System interface packet width
• `CFG_MIOW : IO data width (number of data pins)

Registers

• None

Simulation

cd $OH_HOME/mio/dv
./build.sh
./run.sh dut_mio.bin tests/test_random.emf