TMR1是16位宽度的TMR1由2个8位的可读写的寄存器TMR1H和TMR1L组成。
TMR1有专门的启停控制位TMR1ON，通过软件可以任意启动或暂停TMR1计数功能。
T1CON:TIMER1 CONTROL REGISTER
bit7-6 unimplemented :Read as ‘0’
bit5-4 T1CKPS1:T1CKPS0:Timer1 input Clock Prescale Select bits
11=1:8 prescale value
10=1:4 prescale value
01=1:2 prescale value
00=1:1 prescale value
bit3 T1OSCEN:Timer1 Oscillator Enable Control bit
1 = Oscillator is enable
0 = Oscillator is shut-off
bit2 T1SYNC:Timer1 External Clock Input Synchronization Control bit
when TMR1CS = 1
1= Do not synchronize external clock input
0= Synchronize external clock input
when TMR1CS = 0
This bit is ignored .Timer1 uses the internal clock when TMR1CS = 0.
bit1 TMR1CS:Timer1 Clock Source Select bit
1 = External clock from pin RC0/T1OSO/T1CKI
0 = Internal clock
bit0 TMR1ON:Timer1 on bit
1 = enables timer1
0 = stops timer1