38K0 Datasheet, PDF (26/133 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

38K0 Group
USB Function Control Circuit (USBFCC)
Block Diagram
The following diagram shows the USBFCC block diagram. The cir-
cuit comprises:
(1) Serial Interface Engine (SIE)
(2) Device Control Unit (DCU)
(3) Internal Memory Interface (MIF)
(4) CPU Interface (CIF)
USB Function Control Circuit
DCU control
DCU status
MIF control
SIE control
SIE status
Transmit/Receive
data
D0+
D0-
Multi-Channel RAM
Fig. 24 USB Function Control Circuit (USBFCC) block diagram
(1) Serial Interface Engine (SIE)
The SIE performs the following USB lower-layer protocols (pack-
ets, transactions):
•Sampling of receive data and clock, generation of transmit clock
•Serial-to-parallel conversion of transmit/receive data
•NRZI (Non Return Zero Invert) encode/decode
•Bit stuffing/unstuffing
•SYNC (Synchronization Pattern) detection, EOP (End of
Packet) detection
•USB address detection, endpoint detection
•CRC (Cyclic Redundancy Check) generation and checking
(2) Device Control Unit (DCU)
The DCU manages the following USB upper-layer protocols (ad-
dress/endpoint and control-transfer sequence):
•Status control for each endpoint
•Control-transfer sequence control
•Memory interface status control
(3) Memory Interface (MIF)
The MIF controls the flow of data transfer between the SIE and the
multi-channel RAM under the management of the DCU.
(4) CPU Interface (CIF)
The CIF performs the following functions:
•Mode setting via registers, DCU control signal generation, DCU
status signal reading
•Interrupt signal generation
•Internal bus interface control.
Rev.3.00 Oct 05, 2006 page 26 of 129
REJ03B0192-0300