NEC uPD98502 Network Cables User Manual


 
CHAPTER 1 INTRODUCTION
54
Preliminary Users Manual S15543EJ1V0UM
1.10 Reset Configuration
The falling edge of Clock Control Unit (CCU)s reset line (RST_B) serves as the
µ
PD98502's internal reset. The
System Controller generates the IBUS reset signal using RST_B for the global reset of the
µ
PD98502. After 4 IBUS
clock (SDCLK), the System Controller deasserts the IBUS reset signal synchronously with IBUS clock (66 MHz). And
also the System Controller generates the internal Cold Reset signal and Hot Reset signal for performing the cold reset
of VR
4120A. Once power to the
µ
PD98502 is established, the System Controller asserts internal CLKSET signal,
internal Cold Reset (COLDRST#) signal and internal Hot Reset (HOTRST#) signal at the falling edge of RST_B
signal. After 2 VR
4120A clock (internal VCLOCK) cycles at rising edge of the RST_B, the System Controller deasserts
the CLKSET signal synchronously with clkm. Then 16 clkm cycles (see section 1.12) at the rising edge of the
RST_B signal, the System Controller deasserts the COLDRST# synchronously with clkm. And also the System
Controller deasserts the HOTRST# synchronously with clkm after 16 clkm clock cycles at deassertion of the
COLDRST#.
Figure 1-11. Reset Configuration
ATM Cell Processor
USB Controller
Ethernet
Controller
#1
System Controller
V
R
4120A RISC
Processor Core
µ
µ µ
µ
PD98502
RESET
ibrsetibrset
ibrset ibrset
reset
CLKSET
COLDRST#
HOTRST#
cresetb
macwrst
macwrst
usbwrst
usbwrst
atmwrst
atmwrst
macrdy
macrdy
usbrdy
atmrdy
atmrdy
usbrdy
Ethernet
Controller
#2
ibrset
mac2wrst
mac2rdy
mac2wrst
pcirdy
SDRAM
UTOPIA2
Boot ROM
USB
MII
MII
PHY-MGR
UART
IBUS
PCI
Controller
ibrset
pciwrst
pcirdy
pciwrst
mac2rdy
PCI