From 378567da4e40a31efed349fbe68deebd14079b94 Mon Sep 17 00:00:00 2001 From: Øyvind Harboe Date: Fri, 1 Apr 2011 00:00:39 +0200 Subject: mips: illustrates how to improve performance MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Do not require unecessary roundtrips for clocking out data. Signed-off-by: Øyvind Harboe --- src/target/mips_ejtag.c | 17 +++++++++++++++-- src/target/mips_ejtag.h | 1 + src/target/mips_m4k.c | 8 ++------ 3 files changed, 18 insertions(+), 8 deletions(-) (limited to 'src/target') diff --git a/src/target/mips_ejtag.c b/src/target/mips_ejtag.c index 9df8a021..087be076 100644 --- a/src/target/mips_ejtag.c +++ b/src/target/mips_ejtag.c @@ -146,11 +146,24 @@ int mips_ejtag_drscan_8(struct mips_ejtag *ejtag_info, uint32_t *data) *data = buf_get_u32(field.in_value, 0, 32); - keep_alive(); - return ERROR_OK; } +void mips_ejtag_drscan_8_out(struct mips_ejtag *ejtag_info, uint8_t data) +{ + struct jtag_tap *tap; + tap = ejtag_info->tap; + assert(tap != NULL); + + struct scan_field field; + + field.num_bits = 8; + field.out_value = &data; + field.in_value = NULL; + + jtag_add_dr_scan(tap, 1, &field, TAP_IDLE); +} + static int mips_ejtag_step_enable(struct mips_ejtag *ejtag_info) { static const uint32_t code[] = { diff --git a/src/target/mips_ejtag.h b/src/target/mips_ejtag.h index 63b6093c..aa890d2b 100644 --- a/src/target/mips_ejtag.h +++ b/src/target/mips_ejtag.h @@ -137,6 +137,7 @@ int mips_ejtag_enter_debug(struct mips_ejtag *ejtag_info); int mips_ejtag_exit_debug(struct mips_ejtag *ejtag_info); int mips_ejtag_get_idcode(struct mips_ejtag *ejtag_info, uint32_t *idcode); int mips_ejtag_drscan_32(struct mips_ejtag *ejtag_info, uint32_t *data); +void mips_ejtag_drscan_8_out(struct mips_ejtag *ejtag_info, uint8_t data); int mips_ejtag_drscan_8(struct mips_ejtag *ejtag_info, uint32_t *data); int mips_ejtag_fastdata_scan(struct mips_ejtag *ejtag_info, int write_t, uint32_t *data); diff --git a/src/target/mips_m4k.c b/src/target/mips_m4k.c index 10d3c7da..7530cbd0 100644 --- a/src/target/mips_m4k.c +++ b/src/target/mips_m4k.c @@ -254,18 +254,14 @@ static int mips_m4k_assert_reset(struct target *target) { if (mips_m4k->is_pic32mx) { - uint32_t mchip_cmd; - LOG_DEBUG("Using MTAP reset to reset processor..."); /* use microchip specific MTAP reset */ mips_ejtag_set_instr(ejtag_info, MTAP_SW_MTAP); mips_ejtag_set_instr(ejtag_info, MTAP_COMMAND); - mchip_cmd = MCHP_ASERT_RST; - mips_ejtag_drscan_8(ejtag_info, &mchip_cmd); - mchip_cmd = MCHP_DE_ASSERT_RST; - mips_ejtag_drscan_8(ejtag_info, &mchip_cmd); + mips_ejtag_drscan_8_out(ejtag_info, MCHP_ASERT_RST); + mips_ejtag_drscan_8_out(ejtag_info, MCHP_DE_ASSERT_RST); mips_ejtag_set_instr(ejtag_info, MTAP_SW_ETAP); } else -- cgit v1.2.3