SBE HW400c/2 User Manual

Page of 104
 
HighWire HW400c/2 User Reference Guide Rev 1.0 
 
4.2.16 Device Control Register (DCR) 
 
 
 
15 
B
B
B
B
B
B
 
The Device Control Register (DCR) is a Read/Write register, which controls the CP
timer enable and three resets.  
 
   
The Reset pulse applied to any device must conform to the specifications of that particular device. 
Please refer to the applicable device manual for details. 
Table 46.  Device Control Register (CSR) Offset Address 0x
 
it 7 
it 6 
it 5 
it 4 
it 3 
it 2 
Bit 1 
Bit 0
Re
C
Re
Re
DO
T8
served Reserved  TREN 
served
served
CRST 
110L_RS
ETHRS
 
 
CTREN 
= 0 
CPU Tim
CPU Tim
 
 
DOCRST 
= 0 
De-assert Disk-on-Chip RESET (default state) 
 
= 1 
Assert Disk-on-Chip RESET 
 
De-assert T8110L RESET (default state) 
tate) 
= 1 
Assert Ethernet Switch & PHY RESET (minimum 5us) 
 
 
4.2.17 CPU Timer Register (CTR) 
he CPU Timer Register is a Read-Only register.  It is used for measuring CPU 
ce.  The register value increments once for each tick of the (1.5625 MHz) 
PI serial clock, i.e. once every 640 ns. 
 
 is enabled by writing a “1” to DCR bit 5 (CTREN, see 
Section 4.2.16).  Otherwise, it is held to a count value of 0x00 when DCR bit 5 is “0. 
 
Bit 7 
B
Bit 0 
er disabled (default state) 
er enabled 
 
= 1 
 
 
 
T8110L_RST  = 0 
 
= 1 
Assert T8110L RESET 
 
 
 
THRST 
= 0 
De-assert Ethernet Switch & PHY RESET (default s
E
 
 
 
T
performan
S
The CPU Timer Register
 
Table 47.  CPU Timer Register (CTR) Offset Address 0x16 
it 6 
Bit 5 
Bit 4 
Bit 3 
Bit 2 
Bit 
CTR7 CTR6 CTR5 CTR4 CTR3 CTR2 CTR1 CTR0 
 
 
TR[7:0] 
= 0x00 –> 0xFF 
(when DCR bit 5 = 1) 
CTR[7:0] 
= 0x00 
(when DCR bit 5 = 0) 
C
 
 
 
October 10, 2006 
Copyright 2006, SBE, Inc. 
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