SST89V54RD2 Silicon Storage Technology, Inc., SST89V54RD2 Datasheet - Page 49

• Manufacturer Part Number: SST89V54RD2
• Description: Flashflex51 Mcu
• Manufacturer: Silicon Storage Technology, Inc.

FlashFlex MCU
SST89V54RD2/RD / SST89V58RD2/RD
8.3.1 Capture Mode
Capture mode is used to capture the PCA timer/counter
value into a module’s capture registers (CCAPnH and
CCAPnL). The capture will occur on a positive edge, nega-
tive edge, or both on the corresponding module’s pin. To
use one of the PCA modules in the capture mode, either
one or both the CCAPM bits CAPN and CAPP for that
module must be set. When a valid transition occurs on the
CEX pin corresponding to the module used, the PCA hard-
ware loads the 16-bit value of the PCA counter register (CH
©2007 Silicon Storage Technology, Inc.
FIGURE
CEXn
CCAPMn
n=0 to 4
CCON
8-2: PCA Capture Mode
CF
ECOMn CAPPn CAPNn MATn
CR
0
CCF4
CCF3
0
Capture
49
CCF2
TOGn
and CL) into the module’s capture registers (CCAPnL and
CCAPnH). If the CCFn bit for the module in the CCON
SFR and the ECCFn bit in the CCAPMn SFR are set, then
an interrupt will be generated. In the interrupt service rou-
tine, the 16-bit capture value must be saved in RAM before
the next event capture occurs. If a subsequent capture
occurred, the original capture values would be lost. After
flag event flag has been set by hardware, the user must
clear the flag in software. (See Figure 8-2)
0
PWMn ECCFn
CCF1
0
CCF0
CCAPnH
PCA Timer/Counter
CH
CCAPnL
S71255-10-000
1255 F24.0
PCA Interrupt
CL
Data Sheet
12/07