2-4
Seiko Epson Corporation
S1C31D50 TECHNICAL MANUAL
(Rev. 1.00)
2.2.
System Reset Controller (SRC)
2.2.1.
Overview
SRC is the system reset controller that resets the internal circuits according to the requests from the
reset sources to archive steady IC operations. The main features of SRC are outlined below.
•
Embedded reset hold circuit maintains reset state to boot the system safely while the internal
power supply is un- stable after power on or the oscillation frequency is unstable after the clock
source is initiated.
•
Supports reset requests from multiple reset sources.
-
#RESET pin
-
POR and BOR
-
Reset request from the CPU
-
Key-entry reset
-
Watchdog timer reset
-
Supply voltage detector reset
-
Peripheral circuit software reset (supports some peripheral circuits only)
•
The CPU registers and peripheral circuit control bits will be reset with an appropriate initialization
condition ac- cording to changes in status.
Figure 2.2.1.1 shows the SRC configuration.
Figure 2.2.1.1 SRC Configuration
2.2.2.
Input Pin
Table 2.
2
.2.1 shows the SRC pin.
Table 2.2.
2
.1 SRC Pin
Pin name
I/O
Initial status
Function
#RESET
I
I (Pull-up)
Reset input
The #RESET pin is connected to the noise filter that removes pulses not conforming to the
requirements. An internal pull-up resistor is connected to the #RESET pin, so the pin can be left
open. For the #RESET pin
characteristics, refer to “#RESET pin characteristics” in the “Electrical
Characteristics” chapte
r.
Reset
hold
circuit
Noise filter
Reset
decoder
POR
Clock
generato
r
BOR
Internal reset signals
(Reset group)
SYSRST_H0
SYSRST_H1
SYSRST_S0_0
SYSRST_S0_n
To CPU and peripheral circuits
To CPU and peripheral circuits
To peripheral circuit 0
To peripheral circuit 1
Boot clock
IOSCCLK
Reset request
signal
V
DD
V
SS
#RESET
Reset request from CPU
Key-entry reset
Watchdog timer reset
Supply voltage detector reset
Software reset 0
Software reset n
SRC
Summary of Contents for S1C31D50
Page 461: ...25 1 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 25 Package TQFP12 48PIN ...
Page 462: ...25 2 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 QFP13 64PIN ...
Page 463: ...25 3 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 TQFP14 80PIN ...
Page 464: ...25 4 Seiko Epson Corporation S1C31D50 TECHNICAL MANUAL Rev 1 00 QFP15 100PIN ...