Chapter 15: Serial Port Interface
TX7901 User’s Manual (Rev. 6.30T – Nov, 2001)
15-16
15.8.3 TSEI Data Register (SEDR)
This register is the data register of the TSEI system.
7
6
5
4
3
2
1
0
data7
data6
data5
data4
data3
data2
data1
data0
2
h
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Reset:
0
0
0
0
0
0
0
0
When the TSEI system is configured as a master, transfers are started by a software write to
the SEDR register.
15.8.4 TSEI Data Direction Register (DDCR)
This register may be read or written to at any time and is used to enable or disable the input
and output pins of the TSEI system.
7
6
5
4
3
2
1
0
-
-
TSS_n
TSCLK
MOSI
MISO
-
-
3
h
-
-
R/W
R/W
R/W
R/W
-
-
Reset:
0
0
0
0
0
0
0
0
TSS_n:
Slave Select (low active)
When TSEI is enabled as a slave, the TSS_n pin is the slave select input, regardless of the
value of the DDCR register.
When TSEI is enabled as a master, the function of the TSS_n pin depends on the value of
DDCR bit 5.
0:
The TSS_n pin is used as an input to detect mode fault errors. A low TSS_n pin
indicates that some other device in a multiple master environment is acting as a master
and is trying to select this device as a slave. To prevent harmful contention between
output drivers, a mode fault is generated which will disable the module and tri-state all
output pins.
1:
No mode fault will be generated.
TSCLK:
Serial Clock Signal
When TSEI is enabled as a slave, the TSCLK pin will function as an input, regardless of the
value in the DDCR register.
When TSEI is acting as a master, bit 4 in the DDCR register must be asserted to enable the
TSCLK output.
TSDMOSI:
Master Output, Slave Input
When the TSEI system is enabled as a slave, the TSDMOSI pin acts as the slave serial data
input regardless of the state of DDCR3.
Summary of Contents for TMPR7901
Page 1: ...TX System RISC TX79 Family TMPR7901 Symmetric 2 way superscalar 64 bit CPU ...
Page 14: ...Handling Precautions ...
Page 15: ......
Page 17: ...1 Using Toshiba Semiconductors Safely 1 2 ...
Page 41: ...4 Precautions and Usage Considerations 4 2 ...
Page 42: ...TX7901 User s Manual Rev 6 30T November 2001 DOCUMENT NUMBER M 99 00004 07 ...
Page 43: ......
Page 259: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 1 13 Removed ...
Page 260: ...Chapter 13 Removed TX7901 User s Manual Rev 6 30T Nov 2001 13 2 ...