SST89E554RC-40-C-NJE Silicon Storage Tech, SST89E554RC-40-C-NJE Datasheet - Page 50

• Manufacturer Part Number: SST89E554RC-40-C-NJE
• Description: Semiconductors and Actives, Microprocessors, Microcontrollers
• Manufacturer: Silicon Storage Tech

EOL Data Sheet
8.0 PROGRAMMABLE COUNTER ARRAY
The Programmable Counter Array (PCA) present on the
SST89E/V554RC and SST89E/V564RD is a special 16-bit
timer that has five 16-bit capture/compare modules. Each
of the modules can be programmed to operate in one of
four modes: rising and/or falling edge capture, software
timer, high-speed output, or pulse width modulator. The 5th
module can be programmed as a Watchdog Timer in addi-
tion to the other four modes. Each module has a pin asso-
ciated with it in port 1. Module 0 is connected to P1.3
(CEX0), module 1 to P1[4] (CEX1), module 2 to P1[5]
(CEX2), module 3 to P1[6] (CEX3), and module 4 to P1[7]
(CEX4). PCA configuration is shown in Figure 8-1.
8.1 PCA Overview
PCA provides more timing capabilities with less CPU inter-
vention than the standard timer/counter. Its advantages
include reduced software overhead and improved accuracy.
The PCA consists of a dedicated timer/counter which
serves as the time base for an array of five compare/cap-
ture modules. Figure 8-1 shows a block diagram of the
TABLE
©2007 Silicon Storage Technology, Inc.
FIGURE
CPS1
0
0
1
1
8-1: PCA T
CPS0
8-1: PCA T
0
1
0
1
IMER
PCA Timer/Counter
IMER
/C
OUNTER
16 Bits
/C
(maximum rate = f
OUNTER AND
External clock at ECI pin
Timer 0 overflow
12 Clock Mode
S
OURCE
f
OSC
f
OSC
/12
/4
C
OMPARE
OSC
/8)
50
/C
APTURE
PCA. External events associated with modules are shared
with corresponding Port 1 pins. Modules not using the port
pins can still be used for standard I/O.
Each of the five modules can be programmed in any of the
following modes:
•
•
•
•
•
8.2 PCA Timer/Counter
The PCA timer is a free-running 16-bit timer consisting of
registers CH and CL (the high and low bytes of the count
values). The PCA timer is common time base for all five
modules and can be programmed to run at: 1/6 the oscilla-
tor frequency, 1/2 the oscillator frequency, Timer 0 overflow,
or the input on the ECI pin (P1.2). The timer/counter source
is determined from the CPS1 and CPS0 bits in the CMOD
SFR as follows (see “PCA Timer/Counter Mode Register
(CMOD)” on page 28):
16 Bits Each
Module 0
Module 1
Module 2
Module 3
Module 4
Rising and/or falling edge capture
Software timer
High speed output
Watchdog Timer (Module 4 only)
Pulse Width Modulator (PWM)
M
ODULES
SST89E564RD / SST89V564RD
SST89E554RC / SST89V554RC
(maximum rate = f
External clock at ECI pin
P1.3/CEX0
P1.4/CEX1
P1.5/CEX2
P1.6/CEX3
P1.7/CEX4
1207 F34.0
Timer 0 overflow
6 Clock Mode
f
f
OSC
OSC
/6
/2
FlashFlex MCU
OSC
S71207-08-EOL
/4)
T8-1.0 1207
1/07