TC1796
Peripheral Units (Vol. 2 of 2)
Micro Second Channel (MSC)
User’s Manual
21-27
V2.0, 2007-07
MSC, V2.0
21.1.4
I/O Control
The types of I/O control logic for the MSC module I/O lines are shown in
The downstream channel generates five output signals that control eight MSC module
outputs, split into four chip select outputs, two clock outputs, and two serial data outputs.
The upstream channel has one input signal.
Figure 21-19 I/O Control
All MSC module I/O signals are controlled by bit fields that are located in the Output
Control Register OCR.
21.1.4.1 Downstream Channel Output Control
As shown in
and
, the active phases during downstream
channel operation are indicated by three enable signals:
•
ENL indicates the SRL active phase of a data frame
•
ENH indicates the SRH active phase of a data frame
•
ENC indicates the active phase of a command frame
The chip select output control logic of the MSC uses a signal compressing scheme
(similar to the interrupt request compressing scheme in
) that allows each
of the three enable signals to be directed via a 2-bit selector to one of the four chip enable
MCA05813
Downstream
Channel
Clock & Data
Output
Control
FCLP
FCLN
SOP
SON
FCL
SO
EN0
EN1
EN2
EN3
Chip Select
Output
Control
Data Input
Control
SDI[7:0]
SI
Upstream
Channel
ENL
ENH
ENC
MSC Module